This is part of the small collection I have already bought (Turns out the overwhelming bulk of it has checked out, but there are a couple of bummer pieces in there too), and after having done some research I haven’t found an example that has the back completely hollowed out like this one. I saw in the database on this sub-forum that some of the iterations have the back "scooped out", but those seem to have a different pattern on the back, and are generally more detailed.

I don’t see a maker’s mark anywhere on it, and it seems to be made of a pot metal.

Something makes my Spidey-Sense tingle on this one, but he did say that he’d take back anything that didn’t pass muster.

Any guidance is much appreciated here!