So today I finally got to unpack it and it was a surprise - all of the predictions and suggestions were wrong.
First impression: Ugh. It's dirty. very dirty.

What's strange is that, unlike the IBM 5251 Beamspring, which this keyboard is a copy of (at least layout wise), it features a male plug, rather than the 5251 female one.

As for switches, it's more of a disappointment. Keytronic Foam and Foil, with the Keytronic Spokane Branding. they're not terrible but probably in need of new pads and I'm too lazy for that.

The underside is very plain, there's absolutely nothing apart from a little volume knob and the speaker holes


Opening up, we see the PCB and the speaker + volume knob


I'd imagine the speaker sounds absolutely awful given the age and it being a keyboard speaker, my money is on it acting as a solenoid replacement, I doubt it's a very good one though

the front side of the PCB doesn't have anything special, I have no idea what the pins on the far top left are though

I'm assuming this is just standard PCB labeling


All in all a pretty interesting board, can't say I'm too happy with it turning out to be Foam and Foil, but eh, what can you do.