I'm trying to identify this connector-- it looks to be 1.27mm pitch with a decent chance of being from a Japanese manufacturer. (It mates to the memory expansion bus of an old Japan-only Sharp x68000 computer if that helps.)
JAE TX24/TX25 family looks similar, but I've yet to find anything with the distinctive little 'notch' in the corners or the same mounting method, but I recall seeing something like that in the past. There are no other identifying marks in general. Typically just the usual four digit year/week date code.
Apologies for the large image; I figured the resolution is necessary for a good look.