I tried to get my camera to take a picture of it, but it only take really fuzzy pictures right now (I think there may be a sasquatch hiding around here somewhere.) Anyways, I'll try to describe it, under the optical interrupter for the mouse wheel (the area marked U1) there is a square via and to it's left a round one. Those are the A and B signal from the interrupter. They should work with any grey code rotary encoder.
I think that I will have to use an MX switch, I've got a whole keyboard filled with blacks in my garage doing nothing because steel series under estimated the need to debounce mechanical switches.