Somebody ground/sanded the reverse down. Used to be folks would do this to a coin (cents worked best because copper is soft). Once smooth they would engrave a sentiment of some sort. They are commonly referred to as love tokens. Perhaps this was a love token in the making. Or could simply be a bored kid in shop class. Either way, this occurred after leaving the mint.
glue it and put it on the bottom of chairs to help them slide on metal floors. ... thinking commonly outside of the box of commonly thinking ...
It almost looks like someone filled in the reverse with solder. It looks like some got onto the obverse too.
Heat the coin and if the reverse clears up tmeyer got it right..Bud and I think he may well have gotten it right. <-Bud in agreement with tmeyer
This is exactly what I was thinking. Someone was experimenting with solder and decided to fill the reverse in. The obverse has some obvious overflow.
Good call. I've done it myself. Also looks to me like the solder side is slightly convex from the surface tension of the solder when it was molten which lends some verification to your theory.