Really no automotive expert (fix what I have to). Only open it the one, think it came out of an early 80's Ford P.O.S.(as describes most Ford cars), been a while. A lot of stuff is made to be replaced as a unit, instead of just the failed component. Likely more trouble then it's worth. If you were really set on using wiper motors for something, might be worth drill out the rivets just to see what's inside. I would think they are easy and cheap to find at the salvage yard. Kind of depends on if you have the spare time, the curiousity, and the tools.