My main interest in collecting 18th century German coins, are to collect by the mint marks that were used by the Munz Commission. The mint marks and design changes during the Munz Commissions inspections of the mints at Brunswick-Luneberg-Hannover and Brunswick-Wolfenbuttel are very interesting and the varieties can keep you searching for along time. It is very time consuming try to find the coins with the mint marks used by the Munz Commissions. But, you can make it easier and more interesting by looking for the design changes like the 1/6th Thalers in the photos. 1/6th Thaler 1788 C. minted at Zellerfeld Mint during the Munz Commission Compare the first photo to the second one. With these photos you can see the change in the size of the shield / coat of arms, and the engraver has moved the 1/6th from touching the rim on the 1788 coin. You can see the outline from were it use to be near the rim. Also when comparing the photo's you will notice that the numbers used for the date and the separation from the shield have changed. My guess is that 1788 was the year they were making the design change. I only say this, as there is a variety of the 1788 that has the same design as the 1789. Both coins have the C. (Commission) mint mark that was used the Zellerfeld mint for Brunswick-Luneberg-Calenberg-Hannover. 1/6th Thaler 1789 C. minted at Zellerfeld Mint during the Munz Commission The Munz Commissions mint marks are as follows. Mint marks used at the Brunswick-Luneberg-Calenberg-Hannover mints : At the Clausthal mint : C 1751-53 / 1790-92. The Hannover mint : *.C.* 1763-68. The Zellerfeld mint : C. 1719-23 / 1731 / 1778-79 / 1786-91. Munz Commission mint marks used at Brunswick-Wolfenbuttel mints : Brunswick mint : M.C. 1779-1806 and 1820. At the Zellerfeld mint : C*C* 1711-12 / 1719-23. During 1731 *C* was used.
Sorry I should have showed the mint mark. The mint mark is under the Wildman in the the new posted photo. The mint mark is the letter C, but other mint marks were used by the Munz Commission which is explained in the above post.
This is just one more thing that I know absolutely nothing about, but enjoyed reading about it. I wish you continued success. Thanks