Scott, that sounds like a lot of work. First step would be to compare the 123 to the 106 using the Parts Lookup exploded views. Wouldn't hurt to compare the 107 exploded drawings as well. Might be easier to cut the QA mounts off of the 106 and weld them onto the 123. Don't forget to mount the QA studs (Frankenstein bolts) to the 123 frame as well. For those you'll need to locate where to drill the holes then use nuts to hold them on. The 106 will have captive nuts (as in welded on) for the QA studs. I bet you could find a roller 1x7 chassis for fairly cheap and if you were to sell the 106 chassis to a puller looking for a gear drive chassis, you might come out money ahead.