Saxe-Gotha-Altenburg, 1/24 Thaler, Friedrich III 1766 I'm not 100% sure about the attribution, but the date is right for Freidrich III, and the shield looks right. I haven't been able to find this exact coin on the internet. It looks like it says there are 24 in a thaler and CCCXX (320) in a mark, but the text is a bit worn.
The attribution looks good. The NGC photo isn't all that great, but it says "330 eine Mark reine" or 330 to a pure mark. https://www.ngccoin.com/price-guide...er-km-312-1763-1771-cuid-1150818-duid-1382742 I have recently become interested in understanding denominations and comparing them to other countries. I have not fact checked this site yet, but found it interesting. http://www.personal.utulsa.edu/~marc-carlson/history/coin.html I'd love to see other sources of denomination breakdowns, especially for the German states er .
1806 Great Britain Halfpenny proof restrike- mint error 1807 Great Britain Halfpenny proof restrike 1811 Bank of England 1 Shilling 6 Pence (18 Pence)
Argentina Buenos 'Ayres' 1827 5/10 real, (sorry for the photos, still working with a new setup). They didn't reduce it down to the lowest common denominator (cue math twitch).
A pair of these came yesterday, Jaipur AE 1-2 paisa, RY 22, issued during the reign of Queen Victoria. You can see the Arabic numerals 22 at the 2 O'clock position on the obverse.