I missed this one when I did the section at the back of the 72nd edition Charlton Catalogue. I was not aware of its existence, and as much as I can find out, less than 300 were made.
This copper medal has the nickel 25c insert in it, like the other two medals I did document. However, the other two medals are proof-like (PL) strike quality, while this one is a proof finish.
Here is the one I put in the catalogue:

And here is the new employee token (not in the catalogue):

