Seat Belts
I don't have the seat belts you need but I have some advice.
I have a 65 Chevelle that has tan seat belts and when I got the car they were extremely dirty and I thought I would have to get new ones.
I ended up cleaning them in the kitchen sink with hot water and dish soap and hung them on the clothes line to dry and they now look like they are brand new.
I was amazed at how well they cleaned up.
So, if you have old dirty seat belts try cleaning them first.