I don't think so. The motor has to know how to park itself, and it's interesting to take one apart and see how it works. It's quite a rube-goldberg arrangement, and mostly plastic. Stuff gets worn in there. One thing that might work is to repack it with grease, if you think maybe lubrication would help it. After 45 years, one thing you would surely observe is the grease is just wax now.
There are basically three things that have to happen if you have hidden wipers, which might have been optional in 75.
1. There is a contact that makes up at the bottom of the sweep.
2. This turns on a solenoid activated latch that grabs the crankshaft and won't let it spin, but the motor keeps running.
3. After a half a turn on the ring gear, a second set of contacts needs to open so that the motor will stop.
Of all the stuff in there, where that latch grabs is the item most obviously subject to wearing out. That's a pretty violent operation.
I've never seen the declutching mechanism that allows the crankshaft to stop spinning, but I've never seen one go bad either on a GM car.
