When I was bidding on this one I thought it was something special. . .Upon Reciept I realized that it was just a contemporary stamp on an old coin. 1911 LWC with cross counter stamp. . .
Here is the same stamp on a LMC I purchased a couple of years ago. Also what really tipped me off is that I saw another 1911 LWC on eBay with the same stamp as well after I had purchased this one (which must have sold because I can't seem to locate the listing).
Someone who was very ingenious decided to add to the popular 50 State counter stamp LMC sets with this LSC stamped Puerto Rico. I expect to see stamps in the near future of the other U.S. Territories. . .