The previous note presented details of the reference collection of 1,490 counterfeit shillings of George III dated 1816-1820. This note will look at the metal composition and plating based on the data gathered in the previous spreadsheet. Simple plots of the weights and densities of the pieces allow them to be separated into three groups ‘tin’, ‘copper alloys, brass and copper’ and ‘silver’ counterfeits, mostly consistent with visual observations.
Counterfeit Shillings of George III 1816-1820 (ii) The Observed Metals – Gary Oddie
BNS Research Blog 
I do believe I have found one .
Hi Maria, indeed, these do continue to turn reasonably regularly. Since writing the article, I have probably added another 20 to the reference collection. Please have a look through the other articles in this series and if you have a specimen that is a very different style or metal, or in exceptional condition, I would be interested to hear. The final part of the study, the detailed die analysis, is till ongoing. Thanks, Gary.