if you have a donor car you could do it, dont try to use a gm peice, they were specific to the vehicle. i'll run ya down the basic process. there were several aftermarket t-top manufactures...hurst, Cars and concepts and american, if i am not mistaken the t-tops in chrysler products were made by american or hurst. miradas,cordobas, 300's had been retrofitted with them. sunroofs were the same way for chrysler, they never made thier own. if i am not mistaken some sunroofs were put on during production others were sent to an off site vendor to be done. chrysler still coded the cars for the option , if they were order specifically for it even if they were installed by the outside vendor. progam much like the hemi superstock cars that went to hurst. you would need to make a template out of the car you are taking them out of, take the headliner out to see if any cross bars were cut, modified or moved. in a nutshell, the cars would come into the shop,gaskets would be stripped of the door frame opening, the gasket channels were removed and set aside, headliner was removed...there was something called spreader bars put in the door opening that had a turn buckle in to support the vehcile so it wouldnt collapse during installation, this was used more in GM f-bodies when the entire center was cut out, the templates were put on the roof and measured based on a distance from the windshield.tape up the roof so the tools dont do paint damage. depending on what type of cutting equipment was used, some installers would use a sawsall to get through the heavy roof channel area and switch to a saber saw once they reached the sheet metal, if you should tackle this, let the saw do the job, dont force the cut. once the cuts were made they would file the raw edge sand prefit the frame,make sure the frame has a little bit of play, if it is hard against the sheetmetal opening when you screw it together it will warp the sheetmetal, there should be an inner and outer frame, screw them in place and prefit the glasses. once you have determined you are ready to put it together, get a tube of adheasive/sealer caulk, pullup your tape, lay a heavy bead of caulk around the opening,slide in the frames, screww them together, install the glass for a second to check to make sure the frame didnt trist or warp, pull it out, use a bondo scraper to take off the excess caulk and use a liberally wet rag with preclean on it and clean away... the rest i am sure you can figure out on your own, you said you have a car to use as reference, study the crap out of it. if you should decide to do this.... good luck! i have done a couple hundred t-tops over the years, they havent made kits since the early 90's and nothing for cars of any real vintage. take pictures and post them if you should do it.