Well, after pondering on it for a spell, it occurred to me that maybe somebody might be selling lots of vintage, old, and odd kitchen utensils on eBay.
After searching for a spell, lo and behold, I found a lot of utensils that had one of these contraptions in it.
In the description, it said "a melon scoop marked Citra", but it really wasn't very obvious which of the utensils that one was, but I thought I might do an image search for Citra.
Turns out, Citra is/was a Florida based company that produced promotional and novelty products.
Sure enough, I looked at the one I have that has the wooden handles and there, stamped on the shank, albeit quite faint, "Citra Products of Florida."
It is a grapefruit corer.
I reckon I am gonna have to break down and get me some bifocals.
Citra Grapefruit Corer