18 June 2021
The rollup windows run in lined metal channels. The rear edge and top are a press-in rubber channel available by the foot and are easily replaced, but the rigid, front, guide that serves as backstop for the vent window is another story. They are mechanically complex enough to want to leave alone. Straight lengths of rigid, stainless steeel beaded guide are available by the foot, but no fun to work with. And in the 1960's these guides were curved.
This is much easier, and nearly as good. The one flaw is that the resulting channel for the glass is 1/32" or so too wide, so the glass isn't as tight as the "correct" part, but it is not worn-loose and not sloppy.
The magic chemical here is Permatex Ultra Black or Ultra Gray. It is not ordinary cheap hardware store (or auto store) silicone. It costs more and is worth every cent. Dont by the cheap jelly-like crap.
The requires two full curing times for the Permatex. It's easy, but you have to wait. Hurry it and you will have an unsatisfying mess.
I mounted it loosely in a vise for simplicity.
Get all this crap out. Wirebrush, pick it out, wash in soapy water, let dry. There's decades of dust etc in there.
Using a popsicle stick or something similar, paste a very thin layer of Permatex Ultra Black into the guide. This should be a thin layer. The felt won't be going anywhere, yo don't need to fasten it down.
Tuck the felt into the channel. I had some 1/4" air hard plastic line that was perfect for holding it into place. Doesn't matter. Follow this with smoothing passes of a tiny screwdriver to tuck it into the channel. You don't want baggy or loose spots.
Let the silicone cure. The channel is now complete. The remaining steps finish the visible outer edge.
Using the smallest nozzle, apply a thin bead of goo between the top of the stainelss bead and the felt. This was the hardest part, and it's hard to get a thin even bead, but perfection isn't required; but you want no gaps. A bit extra won't hurt. Resist the attempt to clean up the edges while uncured.
Gently run your finger down the groove to press the felt, lightly, down onto the beads.
This is what it should look like if you look where the felt contacts the bead.
Once again let it cure in this position overnight.
With a brand new single edge razor shave the excess felt off each bead. Tilt the blade into the channel somewhat to make a bevel. Go slow and shear the felt between blade and bead.
Done! The shearing leaves bits and films of silicone on the stainless, which are easily removed with a bit of brass wool.