Good news is I have fixed it! Turns out you were right @grannyknot the arms were bent and an hour with a vice and hammer and trial fitting it now goes up and down very smoothly.

Really appreciate your advice in this!

Now to fix the heater lol

Ash

nice!  glad you got it fixed!

I think this post has really helped me a lot, bent arms are the cause!

Glad we managed to both get them fixed!

Well, mine is not fixed, but after reading this post and looking at your pictures, I inspected the arms inside my doors without removing the regulator.  Sure enough, they are bent!  This issue has bothered me for quite some time, and had no idea what to do.  Next, I must get the regulator out and do the vise and hammer treatment.  Quite a relief just knowing what to do.

Especially interesting to see how the hinged arm managed to bend (noticeably) along its long axis.  If it was just a flat piece, that would be hard to do.  The stamped-in kink near the centre pivot point seems to be the culprit.

I can only guess that after the car has been sitting for 10-20 yrs the grease gets hard, crap accumulates in the runners and channels and when someone goes to roll the window up or down that it sticks or jams. Then they force it and those arms bend,  any other theories?

I would have to agree, It could be argued that i forced it when it was stiff just before it popped off the runners.

I'm sure the only way to damage the arms is to use too much force when rolling up the window.  This was done to my car before I got it, so the windows never worked properly.  I had no idea what the regulator arms were supposed to look like, until now!

Thanks to the people who contributed to this post, my driver's side window rolls up and down normally for the first time since I've owned the car.  I took the regulator out, bent and hammered the arms back into the correct shape, and it works great!  Now to do the passenger side, apparently it had the same gorilla on the window crank.