Here'* one response I got from a newsgroup:
I found that there was a TSB released in 1996 for the early model sunroof seals, replacing the original sunroof seal with a newer one-piece design. The part number is 12371670 and it lists for around $71. I ordered mine through www.gmpartsdirect.com
for $42 plus shipping.
For you do-it-yourselfers out there, it took about 30 minutes to install. Remove the 3 Phillips screws from the front edge of the sunroof and slide the trim ring back. Open the roof to the vent position and remove the 3 Phillips screws on each side of the glass... the glass will lift right out. The old seal pulls right out of the channel that runs around the edge of the glass panel, but there is quite a bit of adhesive along the side where the two ends of the seal join up. You've gotta scrape all the adhesive out of the channel before installing the new seal. Once that'* clean, press the new seal into the channel... no adhesive is necessary. You'll need a rubber mallet to set the seal properly. Once it'* in, reinstall the glass panel, but only lightly tighten the 3 screws on each side, as you'll need to cycle the roof closed a few times as you adjust the glass height and position. The panel should be flush with the top of the car, and the back of the glass should be just a little higher than the front - about 1 mm or so - to keep wind noise down. With the roof closed, you should be able to slide a business card all the way around the sunroof (between the roof and glass panel) with only slight drag. Once you have it all adjusted, tighten it up and cycle the roof a few times to make sure everything'* OK.
For me, it was $50 and an afternoon well spent. Wind noise is gone completely, and now that the drain hoses are fixed, it stays dry, too. If anyone would like full instructions from the shop manual and/or the TSB info, let me know.