Bill, I think that utility panel needs some cleaning!
I ended up using two single 10K pots on my build (couldn't find a quality dual gang one). I got these nice small ones on ebay. Worked fine.
http://www.ebay.com/itm/232099688337
Btw, for those of you using conversion MH boards in a dedicated, you should know that you likely need to add a varistor (Bill sells them) for the X-Linearity adjustment to work. It wasn't populated on my board. After adding the one from Bill it worked like a charm. YMMV.
-Jeff
Here's a few eBay pots that look a little bit more original and have 1/4" diameter shafts and are dual-ganged as well...
example1
example2
Here's a nice looking single one on eBay
Link.
There appear to be many to choose from on eBay. Maybe
AliExpress is another place to look for deals on pots.
example1
example2
Re: "panels needs cleaning!"
Yeah I know huh. That SW is one of the 4 machines that's been sitting in my garage waiting to be restored. Trust me, none of the finished games in the house look like that. It'll look practically new when I'm done with it, maybe within 2017, I hope.
Yes, the conversion-version MH boards were shipped from the factory with one VDR missing, maybe to save a little cost as they were intended to operate along with a T-to-MH or SD-to-MH converter that provides its own VDR. Since there was one on the converter board, the one on the mainboard wouldn't do anything at all because its output wasn't carried through the converter. So, for anyone still planning to use the converter, don't worry about it, but anyone using/changing a conversion-version MH board in/to a dedicated setup, yes, you'll have to add the missing VDR and yes, I sell the little BXVDR board for this purpose for $5 each. The accuracy of the BXVDR reproducing the exact same response of the original Atari VDR component is extremely good, practically perfect.
For MH, I also sell the BX287 module programmed to replace the BPROM at 6C for $20. It's 6H on Quantum (same part). I'm out of these atm but I'll assemble more asap.
Wish I could say that I had produced a LETA replacement but I figured why bother since Vectorlabs makes one. I was planning to produce a new QPE PCB for MH as well but the last time I brought it up, nobody responded so since apparently there was low interest and there are some other sources for them already then I didn't worry about it.
Bill B.