These items were first collectively catalogued by Edouard Frossard, a member of the American Numismatic and Archaeological Society, and published in New York in 1899 (limted edition of 100 copies). The work was (thankfully) reprinted in 1977.
Many of these jetons were struck in both silver and copper, gold ones being struck specifically for the King's cabinet.
These items have been officially restruck by the French mint over the duration using the same dies (but not necessarily the same bust / die match to the obverse) hence there are numerous vatriations from the originals. Although not quite as interesting and valuable as the originals, they still form part of the series. It is not particularly difficult to tell them apart. Modern ones (that is, during the 1880's) tend to be thick with plain edges and carry the name of the metal used and sometimes a hallmark and serial number (not always). The beading is also generally bold and simply `too good to be true' to be an original.
Here's an example of a couple such jetons. The first one (silver) is an 1880's re-strike of a 1755 jeton, sturck at Paris mint using original dies to satisfy collector demand for these. The reverse shows the legendary ship of the Argonauts, complete with ther prize of the golden fleece hanging from the mast. Probably signifying the richness of the `prize' of their colonies, as well as the spirit and reward of their adventure. The second is a 1755 original struck in copper. The obverse shows a fair amount of wear and tear which to me highlights the fact that these items indeed ended up in circulation (more often than not) alongside official coinages. Note the slight variation in bust type between the original and the re-strike. The original has the king draped in lion skin.



