I looked to see if there was another ZVEX pedal that was close.
Sure enough, the "Distortr" has the pots in the exact same position it looks like!
The pot needs to be moved over.
In the Distortr, there are two, but the one that is similar to the Basstortr looks to be in the same Y position, but is aligned with the wiper of the pot on the X-axis. The Basstortr appears to line up with the inner-edge of the Volume pad, which I think is Pin 1 and the ground pad! So, I just need to move it outboard and I think it will work!
Hope so since I have not heard back. I'll mark up a paper template and ensure works first.