Altona Type 1
The Altona Type 1 variations are the first and original versions of the 1 skilling 1771. A total of 8 obverse and 12 reverse dies were made, all by Johan Henrik Wolff, who also produced the dies for all later Altona variations. Mintage was limited to just over one million coins between 1771 and 1773. Type 1 is characterized by the small upper “1” and the square, diamond-like rosettes.
The first two obverse dies are also characterized by the "C"s, which form spiral shapes. However, they differ in that the “7”s point in different directions: AO101 points downward, while AO102 points upward. The reverse dies show a development, marked in green below, in which the intersection of the “K” moves upward in Type 1b. In addition, the “7” appears to become somewhat larger.
Altona Type 1c is a variation that appears somewhat out of place and consists of only one coin: A121. If it did not share an obverse die with contemporary Type 1b coins, it could have been classified as Altona Type 2. This coin is probably best known for the extra dot after "DANSKE", but the most peculiar feature is that we can see changes in three fonts that also appear in Altona Type 2 seven years later: the “N” with shorter end lines; the “M” with thinner and longer upper strokes, with the left side of the right leg partly removed; and the “1”s with somewhat shorter and thicker “feet”. This “mystery”, however, is explained by the fact that Wolff was instructed to make an additional 16 pairs of dies in early 1773. These dies were never used at the time, but were instead stored for possible future mintage.
Altona Type 2
Although more than 6 million 1771 skilling coins had been minted at the Copenhagen Mint between 1773 and 1775, mintage of the 1771 skilling did not resume at Altona until 1779. During the period 1779–1781, however, Altona took over as the main producer of 1 skilling coins, with more than 6 million coins struck.
The minting processes at Altona and Copenhagen appear to have been quite different. While Copenhagen seems to have followed some form of chronological or sequential system for using its dies, the Altona Mint appears to have maintained a pool of dies and used whichever dies were in the best condition. This is particularly evident from the 1779–1781 mintage, when Altona Types 2–4 were struck using 74 pairs of dies. Pairings between Type 2 and Type 3 dies are therefore the rule rather than the exception. We have even identified a Type 3 obverse die that was paired with both Type 2 and Type 4 reverse dies (AO352).
As with Altona Type 1, Altona Type 2 is characterized by the small upper “1”. It differs, however, in the upper rosettes, which are missing two leaf spikes. As a result, they point downward in Types 2a and 2b, to the right in Type 2c and to the left in Type 2d. As shown in the table below, the “L” develops from Type 2b into a form in which the upper stroke is cut on the right side. Altogether, we have identified 12 obverse and 11 reverse dies belonging to Altona Type 2. All of these dies were made in early 1773 and then stored for more than six years. This also explains their close resemblance to the obverse and reverse dies of Altona Type 1.
Altona Type 3
While the differences between Altona Types 1 and 2 are subtle, Wolff made clear changes to both the obverse and reverse dies for Altona Type 3. The "C"s on the obverse now start and end in more pronounced circular curls. There is more space between the pearls of the crown, and the “7”s are longer and rest on the lower part of the "C"s. The reverse dies also change substantially. The upper “1” becomes larger, thicker and somewhat taller, with wider “feet”. The “N” develops a broader end stroke on the left leg and begins to lean to the right. The “K” becomes wider, while the “M” reverts to the earlier shape used in Types 1a and 1b. From Type 3b onwards, the broad end stroke on the left leg of the “N” and the end stroke at the upper right of the “K” disappear. The “A” also becomes less pointed at the top. From Type 3c, the left “foot” of the upper “1” is shortened and the end stroke at the upper right of the “N” disappears. Further minor changes include shorter and narrower “feet” on the lower “1”s, an uneven cut on the left side of the right leg of the “A”, and removal of part of the left side of the right leg of the “M”.
The Altona Type 3 mintage, involving 37 obverse and 23 reverse dies, probably took place in late 1779 and during the first quarter of 1780. These dies were frequently paired with Altona Type 2 dies.
Altona Type 4
Altona Type 4 is characterized by a longer and thinner upper “1”, with wide “feet” and a top that shows a hint of an arrowhead. The “M” still has a long middle leg, while the lower “1”s are straight and have no distinct arrowheads. Wolff also made the “N”s with more complete end strokes. As shown in the table below, the upper “1” changes as early as Type 4b, becoming thinner, with narrower “feet” and a less pronounced arrowhead. The “A”s revert to the shape with the uneven cut on the right leg. From Types 4c to 4e, the “M”s revert to the Type 2 form with thinner and longer upper strokes. From Type 4d, the “K” returns to the slimmer form with pronounced end strokes, similar to the “K”s used in Types 1 and 2. From Type 4e, the “7” becomes smaller, with somewhat thicker strokes. Finally, in Type 4f, the “M” changes back to the form with shorter and thicker upper strokes.
We have identified 24 obverse and 31 reverse dies belonging to Altona Type 4. Pairings between Type 4 and Types 2 or 3 appear to have been relatively uncommon. In fact, we have found evidence of only two Type 3 obverse dies — AO352 and AO368 — that were paired with Type 4 reverse dies during the minting process. We believe the Type 4 dies were made between March 1780 and July 1781.
Altona Type 5
Mintage of the 1771 skilling paused at Altona during the second half of 1781, as it did in Copenhagen. Production resumed in November 1782 at a scale similar to that of 1780. The timing was therefore unfortunate when Wolff went on sick leave between April and September 1783. To ensure an adequate supply of dies, 36 pairs made by Johan Ephraim Bauert were sent from Copenhagen. The result can be seen in 15 known die pairings between Altona and Copenhagen dies:
A503-D, A604-C, A633-B, A634-B, A634-C, A703-B, A705-C, A705-D, A706-B, C545-A, C562-A, C604-A, C606-A, C607-A, C608-A
Altona Type 5 is characterized by the arrow-shaped lower “1”s in combination with the upper rosettes, which still lack two leaf spikes. Several letter forms had changed since 1781: the “N” has a long upper-left end stroke; the “A” has a straight cut along the lower line; the “7” is somewhat larger and thinner; and, from Type 5b onwards, the right leg of the “M” is again cut on the left side while part of the upper-left section is removed. We have registered 22 obverse and 16 reverse dies belonging to Altona Type 5. Most of these dies were used during the latter part of 1782 and the first few months of 1783. However, we can see some reuse of Type 5 dies extending into the second half of 1783.
There is a clear development in the lower “1”s. In Types 5a and 5b, the arrowhead is broad and relatively flat. From Type 5c, it becomes less pronounced. From Type 5d onwards, the arrowhead becomes taller and the “feet” take on a more circular shape.
Type 5e introduces another significant change: the middle leg of the “M” is cut so that it becomes shorter than the left and right legs. It is also worth noting that Wolff cuts the “M” in two different ways, depending on its basic form: 
For “M”s with shorter and thicker upper strokes, such as Type 5e, the cut is fairly straight and horizontal (2a and 2b above). For “M”s with longer and thinner upper strokes, such as Type 6a, the middle leg is formed by two strokes of different thickness, with the thinner stroke extending farther (1a and 1b above). Interestingly, Wolff repeatedly alternates between these two archetypes of the “M”, which can give the impression that two different die cutters were working at Altona. In fact, he alternated between the two forms throughout almost the entire 15-year mintage period, from 1771 to 1785.
Altona Type 6
Altona Type 6 is a direct continuation of Type 5 and is characterized by lower “1”s that lose their distinct arrowhead shape. Although they still retain a hint of an arrowhead, it is now much less pronounced. In Type 6b, their “feet” also lose their circular shape and become shorter and thicker. From Type 6c, the “M” changes back to the second archetype described above. Twenty-four obverse and 40 reverse dies were made with Altona Type 6 characteristics. We believe that approximately half of these dies were used during 1783 and the remainder during the first half of 1784. We also estimate that close to 4.5 million coins were minted during this period using dies sent from Copenhagen, specifically Copenhagen Types 4d, 4e and 5a.
Altona Type 7
Altona Type 7 is characterized by a significant change in the two upper rosettes. As in Altona Type 1, they once again become more diamond-like and symmetrical along both the horizontal and vertical axes. From Type 7b, the lower “1”s take on an arrowhead shape similar to that of Types 5d–5f, although their “feet” are less circular. From Type 7c, there is a clear tendency for the “K”s to lose the pronounced end stroke on the lower right leg, although there are exceptions to this rule. The “L”, however, changes shape from Type 7d onwards, developing a flatter “hook”. From Type 7g, it also becomes somewhat taller.
From Type 7e, Wolff again changes the lower “1”s away from the arrowhead style. He initially reverts to the arrowless shape used during the Type 6 mintage, but then changes course and settles on a new “half-arrowhead” form from Type 7f. Another striking feature of the Type 7e–7g dies is that the “M” changes back to the first archetype, with thinner and longer upper strokes. The upper “1” also develops somewhat narrower “feet”.
Altona Type 7 was produced using a relatively limited number of dies — 69 obverse and 86 reverse — which resulted in high productivity per die but generally low collector scarcity. We estimate that Type 7 dies accounted for just over 20% of the total 1771 skilling mintage, corresponding to an average production of more than 150,000 coins per die. Although some variations are quite rare, several are very common, with estimated mintages exceeding 250,000 coins, including:
A711-A, A770-A, A787-A, A795-A
All Altona Type 7 coins were minted from mid-1784 until production finally ended in July 1785.
