I got the top section near the beltline clearanced today, and plan to start laying up the fiberglass in the next day or so. I think I'm going to put two layers of 4 oz. glass cloth and 2 layers of 1.5 oz glass mat on it. It's weird, but the glass cloth is weighed per square yard and the mat per square foot, so the mat is actually thicker. This layup should get me somewhere close to 1/16" of overall thickness, which I think is plenty. I'll do the final clearancing of the sections as I go, to make sure the leather fits tight.