I had a short hunt at an old house site this morning where I had pretty well pounded the large front yard. The back seems to be pretty short on coins , but thought I would give the back a try today. Again, no coins, but did run across what I think is a pre- WW1 hat device. I suspect it once had a screw back but i can find no exact examples online so far. No id markings on back as to manufacturer and some indentations I haven`t seen on very similar pieces. Let me know if you guys have any knowledge about this one. I included a pic of an example on ebay, it`s the third one. The WW1 issue ones are slightly different. It is one and half inches in diameter.