383GT, thanks for posting that info. They must have obtained a supply of black webbing that would work with the fiero's double take-up reels.
Ssnake-Oyl may be an expensive solution, but at least it works and addresses all the various issues raised including safety, quality, etc (they are the choice for belt restorations on camaros.net, and a local shop specializing in Corvette restorations uses them exclusively). Other than the price, the only drawback is having to ship them your old belts for rewebbing--that can be inconvenient and require parking the car if you don’t have a set of backup belts lying around; however, I’m glad a definitive answer to this has finally been found.