Dave, thanks for your suggestion on this. I tried a test fit today, and the bicycle inner tube strips fit pretty well. They're much thinner than the motorcycle tubes I was thinking about, and in fact, they're slightly loose in the channel. That's not a problem though, there are several ways to tighten the fit. I'll probably want to use the "real" glass tape eventually, but the rubber strips will make it easier to disassemble the frame and remove the glass for future work. I'll need to do that in just a few more weeks so I can mill the side rails for quick-disconnect hardware for the new top. Next spring (when I'm hoping the mountain of maintenance work this car needs will be under better control), I'll need to take the glass out again to have the windshield frame powder coated. If I'm lucky, that will be the end of it.
Incidentally, the rolls of ribbon the guy gave me at the glass shop are indeed sealant only. I have no idea why he gave them to me, except as a last resort to get me out the door. He had told me a week earlier when I placed the order that he would give me a roll of 3/64" setting tape when I picked up the glass. However, when I arrived, he didn't have it, and he couldn't remember us discussing a specific size (even though I had told him twice that it was 3/64" and he had checked to see if they had it). Anyway, that's why I didn't order the tape when I ordered the glass, and that's why I don't have any now.
Jerry, does your glass shop apply the black silicone to keep water out, or is it a cosmetic finish? Should I be concerned that the glass tape alone might not be sufficient to create a watertight seal between the glass and frame? Also, when you said 5/64" inch tape, was that a typo or are you using thicker tape now? The older thread on this project refers to it as 3/64" tape:
http://www.tbucketeers.com/threads/windshield-frame-material.13335/
Darn, I should have added the tape to the order when I bought those mirrors. Speaking of which, they sure are the real deal (just like everything you sell). Excellent quality and exactly the style I was looking for!
Below are a few photos of the work so far. Sorry for the crappy flash shots.
Jack