Spoiler:
In the meantime I am curious!!
It is winkeyless, so a bit old, probably has Clears, and uses Costar stabs, so most likely Costar made, split Backspace, and I think I see a vertical stabilizer on the |\ key, probably big-ass Enter?
I was puzzled by the missing caps, and troubled by the possible effect of years of dust on the switches.
Any ideas?