Just to be safe I ordered a new op-amp
CA3260 Dual MOSFET OpAmp
Doesn't hurt to have a spare on hand, but this has nothing to do with your problem. The various dual opamps available with the OD2, including the MOSFET converstion kit, are all interchangeable.
I'd really like to see a good set of photos of the pedal at this point. Please make them large (but small enough to fit on a single screen at reasonable monitor resolution), well-lit, well-focused close-ups of BOTH sides of the PCB. If your camera has a MACRO setting (most do; it is usually shown with an icon that looks like a flower), use that for these close-ups. There's a tutorial on how to post photos here at THIS LINK
. Alternatively, you can use the forum's attachment function found at the bottom of the posting screen, but this may restrict the size of larger images.
Also, do you have a multimeter available? It would be worthwhile to check the lug-to-lug continuity on the clipping toggle switch in all three switch positions.