My Creative Industries MP was purchased new in 1988. It too has experienced long periods where it sat without use .
The good news - it's still running strong and it's a great wheel.
However ...... many parts are now "unobtanium". When Speedball purchased CI, they did not buy the HP/MP/Jr lines. Forget about manufacturer support for these wheels and you can't buy replacement parts for them - including controllers, foot pedals or splash pans.
I've seen two CI MP wheels come up for sale in my area over the last few years. Both had pedal or controller problems (wheel head was jumpy, didn't handle increasing loads smoothly, or the pedal wasn't responsive). One may have been an adjustment issue in the pedal. The other owner confirmed that she had self-repaired the potentiometer which had improved but not fixed the problem. I don't know what the actual selling price ended up being, but they were asking $300-400 for them. To me, they were not worth anywhere near that amount because of the lack of support/replacement parts.