Based on other Monterey boards, I'm guessing White Alps or Monterey switches. Some of the other similar looking boards I've seen used Mitsumi.
Ones with keycaps this shape and AT layout?
I’ve seen pictures of a couple boards that looked very similar to this with blue Alps switches (down to the same weird-shaped ctrl keycap, ****ty legend alignment, scrunched up ~ symbol, and in the same type of case with little Model F like feet handles on the sides and metal backplate). I don't think I’ve ever seen one that looked quite like this with white Alps, SMK, or Mitsumi switches though.
But yeah, it could be anything; no way to be sure without pulling a cap.