77 GP interior

I might be jumping too early on this. But I might have a chance to get my hands on a 77 Grand Prix. If I do, I want to put new seat upholstery in it. What is in there is nice, but it is not original in regards to design/pattern/style. I am kind of one for originality. Anyone know if anyone reproduces original style seat upholstery for a 77? I haven't been able to find anyone that does. I am pretty sure that 77 Trans Ams had the same front seats, but the rear seat would be different size wise.