New vent-window frames came from Mustangs Unlimited, while the rubber parts and glass run came from CJ Pony Parts, who supplied all of our soft trim items for our Project '66. We had Merv Rego of Classic Creations of Central Florida give us a hand with our project, since there are a few tough spots to get through.
As many parts that are reproduced for the '65-'66 Mustangs, there will always be some part that needs to be reproduced. We recently received the newly repopped '66 standard interior glovebox door, and I'm sure we could make quite a list of items we still want, but it could be worse. Just ask anyone restoring a '71-'73 Mustang or any Mustang II! A few years back, we lucky '65-'66 owners got a bit luckier when KS Reproduction came out with its replacement vent-window frame assemblies. These much-heralded pieces had a small teething problem when first produced but have since been given the green light as a quality part.
Our Project '66 had the typical vent-window frame wear: corrosion, pitting, peeling chrome, and two or three bad paint jobs (I guess they used cheap masking tape with the cheap paint job). With our hardtop painted ("How To Prep and Paint Your Mustang," May '01, page 62), it was time to start filling our door shells back up with glass, regulators, and other items. Before we could do that, of course, we had to install the vent-window frame assemblies. There was no way these unsightly-looking original frames would ever do in the grand scheme of our restoration. A perfect paint job with all-new exterior chrome would be ruined by the ugliness of the original frames. We put a call in to Mustangs Unlimited for a set of these reproduction vent-window frames for Project '66. Follow along as we make our vent windows look worthy of the car they'll be installed on.
Removing the vent-window frame assembly out of your door isn't difficult with a little forethought and a shop manual. Remove the door trim and the hardware first. Next, remove the retaining bolts and adjusters for the vent-window frame, and carefully pull the frame out of the door shell. With the vent assembly on your work surface, remove the nut securing the vent-window tension spring and the spring itself. | 
In order to remove the vent-window glass, the pivot bracket must be removed. Be sure you take a good look at the pivot bushing hardware, so that you'll know how to reassemble it. | 
Stand the vent-window frame on its end as shown and pull the vent glass down into the rubber seal until the top pivot is free of the frame. Pull the glass out of the frame and set it aside for cleaning. |
Remove the screw that retains the front-glass run to the vent frame. We didn't bother removing the vent-frame top seal, since we have new ones for our new vent frames. | 
The front-glass run is pressed into the division bar channel and takes some muscle to separate. Even if you aren't replacing the run, it will have to be removed for access to the division bar-seal retaining rivets. | 
The division bar has two rivets at the lower end that need to be drilled out in order to remove the division bar. |
Using our trusty drill again, we drilled out the small rivets that retain the division bar seal, then the old seal was removed. | 
The division bar is stainless and will clean up quite nicely with hand or machine polishing. | 
One of Rego's tricks is to use a length of tape to secure the new rivets for the new division bar seal into place during swedging. |