emusonacid! legacy

Hello,
I am looking for a place that would sell compatible tack switches so that I can replace the current buttons on my E4k. I noticed that they have an odd square shape that I'm hoping is not proprietary, so I'm looking for a place to buy about 50 of them. Also, my data wheel is not functioning as it should. (I have the problem most people seem to have with the wheel being noisy) Although I could attempt the capacitor fix, I want to first check out the prices of the data encoder.

If anyone has any of these parts sitting around or knows a place that sells them (as cheap as possible), then please let me know.

Thanks.