Some of these vintage sets have keys that don't fit modern equivalents, unfortunately that's just the way the game works sometimes.
I'd hardly call it vintage -- I doubt its even five years old, most likely. No, they just figured it was too complicated to use a stabilizer, like the enter key right below this one used -- so they installed two key
switches one of which, presumably, was a dummy that did nothing.
It made removing this cap exceedingly difficult. Partly of course that's because I don't have a keypuller and was using two screwdrivers and a pocket knife but for as soft and thin as this ABS is, I'm really surprised I didn't tear it.
Yes, I have plans to make an ALPS board. Which won't be using two switches where one is requested. That would be silly. EDIT: just looked at the tag on the bottom. It's an Ortek-2000. Does that narrow it down any?