1965 Mustang convertible door window regulator?

Anyone with hands on? My window was very hard to open and close. Decades ago I had the guts out of the door and figured that the tracks just needed to be lubed.

I finally pulled off the door panel and yes, the rather undisturbed lithium grease had hardened up over the years of inactivity.

More importantly, the rear arm had pulled out of it's roller. I squeezed the clip so it would take a better bite and reinserted the pin into the roller. I re-lubed the three tracks and all the pivot points I could find, then I sprayed dry lubricant into all the vertical glass channels.

The window works more smoothly now but when it gets down to about 3" from being closed it comes to a sudden stop. If I roll the window back up, then lower it with a small amount of pressure on the top edge of the glass, the window smoothly goes all the way down.

What might be going on? Is there a hitch in the quadrant and sector? Do I need to pull it to find out what is going on?