Oberheim Matrix 6 help

[Beerco]

Howdy, new to the site, hope I can find some help here.

I'm the original owner of an Oberheim Matrix-6 that I bought in 1986. After sitting in my basement for about 20 years, I pulled it out and started playing it and remember why I liked this synth so much. It's no Xpander or M-12 but it's mine!

So, I'm going through it cleaning it up and such and there's 3 keys that haven't worked since around 1990 (beer accident I think). I used some electronic cleaner spray to clean under the rubber pads and that jacked them up entirely: the rubber pads (used to detect key press and velocity) swelled up to about 115% of original size and will now not really fit into where they're supposed to. So, instead of 3 bad keys, I'm now up to 7 bad keys.

Does anyone have a junker M-6 they could cannibalize the rubber keyboard pads from or, is there any source for these parts (I'm in the U.S.)?

Second - I've heard that the eproms used to store the firmware only have a life of anywhere from 10 to 20 years. My beast is currently 24 years old and still on the original battery and eprom. Do these eproms lose their program and if so, is there someone set up to copy them? The part in mine is a mitsubishi M5L27256K with 55110F on the second line if that helps any.

The battery says BR2032 but it looks kind of small for that. I imagine any 3v lithium will do?

Thanks in advance for your help.