A couples years age I bought a top for my '82 GTC from Purring Pumas. It was the only one I could find and it wasn't a great fit. I just looked at their web site and the top is no longer listed. Maybe give them a call or email to see if they can help. Contact them at purringpumas.com or
8047 Caminito Mallorca
La Jolla, CA 92037
Here is another place (German) producing replacement Puma tops. I have no experience with them but it appears they offer either vinyl in four colors or cloth in many more. They price out both the top and installation (montage).