I would get the windshield replaced with the later style. You won't have to deal with the half-chrome/half-rubber trim stuff anymore. The newer windshields ($10-20 more?) for a 91/92 740 or the 940 should have the black trim glued permanently to the edge of the glass. Should eliminate the troublesome clips and trim pieces. Otherwise you'd have to scour the junkyards for a decent set of trim pieces and I bet you'd be hard pressed to find any better than your own. My 88 has maybe 1/2 of the rubber left... I figure it's doing ok for its age. It's due for a windshield this year, I can't stand looking through it any more when the sun is low in the sky.
If you need anything for the installation, the windshield shop should be able to tell you, and you can get it either from the dealer (they still sell everything for these cars) or the glass shop if they have it available. Visit the glass installers to see what they recommend, I'm sure they've dealt with every imaginable situation before.

Good luck with it!
--
Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE, 91 244: 808K total