Instead of the two piece original sliding windows, I would like to use full one piece dark tinted windows. I also like this idea of using a Piper style drop window.
First of all, if your windows are due for replacement, I suggest going to .125 thickness instead of the original .080 thickness. The thicker windows will hold up better and not rattle as easily.
If the “U” shaped channel that is at the top and bottom and front of the window frame opening is worn out, it will cause the windows to rattle. If there is still some brush material left in the channels, you can simply squeeze these channels together and tighten up the window fit. If your channels need replacing, you can order them from J.C. Whitney & Co. (312) 431-6102. Order steel core window channel, type 7, size 1/2″ X 3/8′ O.D., (it comes in six foot lengths), stock number 19-3584R, $5.69. You may also find this channel at some automotive glass shops.
I have not found any other source for the vertical brush seals that seal the gap between front and rear door windows. Univair should have these seals. You should have two for each door; one on the back edge of the front window and the other one on the front edge of the rear window. If your vertical brush seals are still in fair condition, but are looking a little bleached out. You can take some black leather shoe dye and touch them up to make them look new again.
You will find the need to seal the upper and lower front corner areas of the front windows where the channel doesn’t meet. You can cut short pieces of foam weather-stripping. The type that comes with an adhesive backing. Most hardware and building supply stores will have it.