I was wasting time last summer looking for anvils on eBay, when I ran across this weird looking set-up. I recognized the little square on top as a jewelers anvil but had no clue what the rest of it was for.
It was cheap enough, and weird enough, so I bought it, figuring that one of my tool buddies would know what the back, where the removable wedge goes, was used for. I clamped it on the shelf with my vises and kind of forgot about it.
Quite a few months later I was looking at pictures on the net when I spotted a picture with a piece similar to this one that had what looked like a Goodell-Pratt hand vise held in it. That prompted me to try my GP hand vise but it wouldn't fit. Another one I had, however, fit like it was made for it.
Apparently the jeweler could insert it when he needed to use it and then remove it when he needed to use the anvil.
Mike