My supergun's been in service since 2002/3, and it's time for a rebuild. I've gathered most of what I need, but I am having problems locating potentiometers for RGB level adjustment. It wasn't a problem before (as the unit was exposed for on the fly tinkering, and the RGB-NTSC convert's pots did the job), but I'm going to be using a enclosure this time around, and I need pots I can remote mount to the side of the case. My local electronic supplier doesn't carry them in the 500-ohm range... any suggestions?