Searching for Copley Medals – seen one?

I am currently revising a paper on the early history of the Royal Society’s Copley Medal for publication. I told part of this story in a post one the H Word Guardian Science blog. Although it is tangential to my main story, because I am particularly interested in the materiality of the medal scheme I would like to trace extant Copley Medals and would be grateful for any help readers can give me.

I am looking particularly for copies of the medal that were made from the original die that was engraved by John Sigismund Tanner at the Royal Mint (his signature ‘T’ is visible on Athena/Minerva’s plinth). One of the very earliest is that given to John Belchier (below, now at the British Museum) – it was awarded in 1737 but he only received the medal after copies were first struck in 1742.

As far as I can tell, this original die was used throughout the 18th and 19th century. Every dozen or so years a fresh batch of medals was struck and then handed out annually until they ran out. By the early 20th century a new die had been produced – this was used for the medals given to Joseph Lister (1902) and Dimitri Mendeleev (1905, below – I think now at the Russian Academy of Sciences). If you compare the images you can see that the face of the figure has changed and the handle on the air pump is straight rather than curly.

I do not yet know just when the die was re-engraved, or who was responsible, although the obverse is now signed TM. The medal changed again substantially in the 20th century, with a new die designed by Mary Gillick, dates 1944 (below, Royal Society). Gillick, also responsible for the young Queen Elizabeth II on British coins 1953-70, dispatched Athena and brought in a portrait of Godfrey Copley.

So far, for the medals awarded between 1737 and 1901, I have only tracked down eight [Edit: this number will increase as I find more – I have 11 as of 11/11/16]. There must be many more out there and I’d love to know of any in private or public collections.

Those I know about, all from the original die, are:

1737, John Belchier, British Museum M.8316

1747, Gowin Knight, British Museum

1752, John Pringle, Royal Society M/132

1770, William Hamilton, British Museum (from Sophia Banks Collection)

1772, Joseph Priestley, Royal Society M/112

1775, Nevil Maskelyne, National Maritime Museum ZBA2361

1776, James Cook, British Museum M.4833

1818, Robert Seppings, National Maritime Museum MED1003

1831, George Biddell Airy, National Maritime Museum MED2122

1858, Charles Lyell, Royal Society M/167

1883, William Thomson, The Hunterian (Glasgow) GLAHM:C.1916.13

I also know of engravings of the 1753 medal given to Benjamin Franklin (in the Gentleman’s Magazine), and the 1750 medal given to George Edwards (on the title page of his Natural History of Uncommon Birds). In addition, the medal given to Edward Sabine in 1821 was sold a couple of years ago, but I don’t know where it ended up.

The complete list of Copley Medallists can be found on Wikipedia. Can anyone help me track down any other extant Copley Medals of the 18th and 19th centuries?