HP 9825 keyboard restoration

[douze-bis]

Hello !
I’m trying to restore an "antique" HP keyboard.

The keyboard belongs to a desktop calculator from the 70s (HP 9825A). It is a little "tired" : sometimes two keystrokes are necessary to input one character, sometimes a single keystroke yields multiple characters, and the overall typing experience is not too good...

My intention is to de-solder the key switches from the keyboard PCB and replace them with new switches.

I have taken the calculator apart to have a better look at the keyboard PCB.
The key switches seem to be from cherry corp. Unfortunately, they are not identical to the switches that can be ordered from (say) WASD.
They are taller, and the two pins are located differently.

For clarity, I have uploaded a few of pictures on my flickr account.
https://www.flickr.com/photos/78824170@N05/sets/72157644101724017/
Pictures 1 and 2 are of the HP 9825 key switch.
Pictures 3 and 4 are of a cherry switch (Cherry MX Brown Keyswitch - MX1A-G1NN).

So... I have a few questions:
- Would anybody know the part number for the HP 9825A key switches ?
- Is there a way to supply these switches nowadays ?
- If not, do other keyboards use the same switches ?
- Or maybe there’s a better/simpler way altogether to restore antique key switches ?

Any help will be greatly appreciated,
Frederic

[Findecanor]

I've had another HP keyboard with both both large and thin keycaps like yours. The switches on mine were Cherry M11 and yours do look not like the same type, but pin- and keycap-compatible.
I don't know what switch type yours are, and I can not find it in any Wiki. Maybe Daniel Beardsmore has a clue.

My Cherry M11 switches were quite fragile and the key feel was not good. I could easily break a switch when trying to pull a keycap and not be able to reassemble it. Several switches were already broken/keycaps missing when I got it.
The switch mount on mine was not Cherry MX-compatible (the cross is too large) but I think there are several other vintage switch types that can take them. Older types of switches (unused, old stock) sometimes appear on eBay.

[olivil]

Love that color scheme!

[esko997]

Board looks very cool, good luck with your restoration!