I redid my quarter glasses earlier last year when I did the body and paint work on my 88. I did consult with Davedacarpainter and a couple guys I work with in the bodyshop. To get the best results you would need to pull the glasses out. I don't see any other way to refurbish them with them in the car. Mine weren't too bad, they werent missing any material or anything. I started by taping off the glass part and blocking them out with 120 grid sandpaper on a flat sanding block to smooth them out. Here at the shop we have two part plastic repair kits that we use on bumper covers and such and that was what Dave and my painter here at the shop recommended I use. So after I blocked them smooth I used the plastic repair kit to build up and fill the low spots in the moldings and smooth them out again. Its a two part material, kind of similar to Bondo. You put it in a caulking gun made for the kit and it mixes it self out through a static mixing tip. You would want to lay that out with a spreader around the glass just like you would with Bondo. After its cured, you would want to block that smooth, (I used 180 I believe). Then, a couple coats of primer. Let that primer sit for 24 hours then sand that smooth with 500-600 grit sand paper, wet. I refinished mine with black basecoat and a semi gloss clear coat, then reinstalled the glasses, along with my interior trim panels. There is a character line that you are going to loose by doing this. I don't think there is any other way to keep that line in the molding by doing it this way and I was ok with that. Working in the collision industry made it easier for me because I had easy access to the materials and the know how. You could go to your local automotive paint supplier and get that two part repair material but it is pretty expensive, I think its about $60 for the kit, then you would have to get the caulking gun, not sure how much that is but its probably expensive too. If you choose to remove them, you will need a roll of Butyl tape to seal up the glasses to the body. They bolt in, and I think there is 9-10 bolts on each glass. There might be other ways to do it but that's how I did it. Heres some pics.
