Some time ago I found a very yellowed clicky keyboard, and knew nothing else about it. Then it spent some ten years in the closet awaiting for me to restore it. Finally when moving I decided to give it a go, and knowing nothing about anything, took the keycaps off using knife or spoon as puller
It turns in the process I managed to break stabiliser wire hooks on a couple of keycaps so I just put everything aside. After a few months, during cleaning, I decided to throw the whole thing. Half a year later I discovered various keyboard communities where I could have gotten help and got it back to working state.
The board itself looked like a model M clone. Fast forward to today, and I got a yellowed Chicony with white Alps. It's the closest thing I found to that board, but I don't think it was it. Stabiliser mechanism is different on Chicony, and I think that the bottom side is different as well, although I am not sure.