If you want to pay to have it done, try a local upholstery shop. I will also add that after you take the top off, you will want to get a set of quarter windows from a car that came without a vinyl top. They are different. I would also weld up the roof where it joins the pillars, and reinforce the roof to the B pillar inside the upper corner of the window opening to avoid cracks. Your first layer of filler should be US Chemical All Metal as it was designed to take the place of the lead GM would have used on a plain roof car. It also will not absorb water like normal Bondo will. Normal Bondo will help to rot your roof out if it is used as a primary layer over a welded repair that has holes from the back side. I detail all of these things in my build thread if you want to see what I mean.