The screws you really need to be concerned about are on the inside....the ones holding the linkage arms togather. From the several units I've looked at it appears that these screws can work loose, jamb up the works, crack housings, in general screw things up. It's these screws that probably cause the other screws to go missing...like when for the 97th time some poor TD owner tears apart the wiper motor only to find nothing wrong because the real problem was a wire shorting out in the rear hatch hinge area.....don't ask how I know that.

The good news is it sounds like you have assembled your collection of motors and now have plenty of spare parts and extra screws. A small piece of vaccum hose slipped over the skinny pointed tail piece of the unit will work to replace that rotted/lost rubber washer. It is much easier to remove that brass colored bracket from the hatch than it is to try and stuff the motor back into it. Clean all that old grease out...It's just old stiff crap after 20 years. When the motor works again and then stops...it's a short in the wiring over the hatch. (if the motor will work out of the car, but not in the car...start looking for that short)

Good luck....these things can make you a bit crazy...you have been warned!! It is really nice to hit the switch and wipe/wash the rear window...you can see so much better.

__________________
Mark
1983 300TD Wagon
Even a broken watch is right twice a day