Hope it goes well for you. We did this on the 100-6 earlier this winter, so the memories of the experience are quite fresh. The glass that we used came from a seller in the US and appeared to be an original piece in quite good condition. The old glass in the frame was badly cracked, but it still had the sealing strips in place to show us how it should be done. The new glass was a little smaller than I would have liked (1/2" or so in each dimension), so it did not fit as far into the frame as a somewhat larger piece would have. We reused the rubber spacer strips that seat in the channels; they were still in good condition. The original seal around the glass was very thin, and the glazing rubber from the local glass shop proved too thick to use. What did work was a roll of that black rubber tape that one uses to stop leaks. That tape is sticky on both sides, and if that is a problem, one could put a layer of thin black electrical tape over it so that it slides into the channel without sticking.
We had a couple of old frames to pick the best corner brackets from. A number of the screw holes had to be drilled out and retapped. We also found enough of the tiny little screws to reuse. Certainly, replacement new brackets and screws would have saved time. But they were weeks away in either California or Britain, as are most parts that we have to order. A couple more hours of careful work sufficed to salvage the screws and brackets.
The scuttle seal also proved difficult to install, because it had deformed in the package and also because it could have been closer to the desired profile. It wanted to pop out of the channel when placed on the car. A little heat and temporary tape to hold it in place helped.
In spite of the challenges, the finished job looks fine. As with most things on these cars, every little step proves interesting.