I believe you must remove the pulley from the motor spindle then carefully pry the “lid” off the motor housing. Mine was only glued with pliable glue at a few places along each side. This will allow you to access the motor housing internals where the potentiometer connections are. If you gently...
I am honest trying to remember how that was assembled. I do know that you are VERY close to having the potentiometer fly apart at that stage... I lost a wiper brush during an “oopsie” right about this stage. For some reason I’m thinking you don’t have to remove that part. I THINK... you need to...
Round belt in groves pulley. Possibly means the strobe idler? You can eliminate the strobe with a shorter belt. Also it seams many parts are interchangeable between michell models. Parts might be available new still. The belts are all the same length also.