Kinda looks like brass / bronze in the photo
That was of course my hope, but I think not. If you look at the
arch of the moveable jaw, or at the wear-prone edge of the
fixed jaw, or at the rough bits of corrosion along the base,
you'll see what the metal looks like (soft, silvery) when the
plating is gone. And scratching the bottom (it's hollow, for
the most part) with an awl or the tip of a knife reveals the
same soft silvery substrate. I
think it's just pot metal
-- judging by the considerable heft, probably zinc alloy pot metal,
rather than aluminum. With a copper wash, if that's likely.
I'm seeing this as what some poor drill operator received to
commemorate 35 years on the job
