wurlitzer model 420 schematic needed

[maxkracht]

Anyone have a schematic for the wurlitzer model 420 tone cabinet? I've only found an unreadable thumbnail so far. I'm mainly interested in the motor control stuff. Someone asked me to fix one and I don't have much experience with rotating speakers. Photo online shows 4 relays, I assume for turning the motor on and off and switching windings for speed control. The actual switches would be on whatever organ it was connected to which isn't available. Does it make more sense to replace with a DC motor to do variable speed instead of figuring out how to rewire the original?