You will need a new regulator. I just replaced both of mine on my 67. Four bolts to remove it. I had issues trying to remove one of the wheels out of the track. It was the top one away from the sprocket end. What I did with the new one, was....I rounded the corners on that arm with my dremel tool. Slid right in. I would say for you to do the same if you replace it.
yeah alright....because my window wasnt working at all, so i took apart the door and got it back on track and it rolls up and down and everything and this was after i had ordered the part so i was sorta unsure if i should cancel it or not, but the window can be pushed down if you lean in and push it down so thats probably not very good theft safety........
anyways...a few days ago i ordered a new regulator from mustangs unlimited and apparently the order never went through and they have no record of me ever ordering it so i thought maybe that was a sign to not get a new one and just refurb the one i have somehow....but i suppose not, thanks