The thread on obsolete $200 strikes was interesting and brought back to mind a "Walking Liberty" "one pounder" that a coin dealer bought from a coin salesman back a few years ago. He purchased a half dozen of these along with their "certificate of authenticity" A few months later another coin salesman came into his store and noticed them in the display case. He looked a the dealer and said "you know those are not one pound of silver don't you." They were clad. The dealer went back into his back room and took a small file and notched one of them and sure enough it was a copper clad token. He was very indignant and being the honest person he was he picked up an electric pencil and scribed "not silver" on the back not once but twice so that no one else would be taken advantage of as he had been.Below is a picture of both front and back of this type of token with certificate.

and below these is a eBay auction for the real thing with the only difference being one says "one pound proof" and the other has "fine silver" on it. Not all of the "display pounders" in the old strike machines were .999 as not all of the casinos gave them out with a jackpot.
also there is no mint mark on the clad strike.