Unfortunately, I do not. I took the original seats that still had some badly beaten up upholstery on them to Auto's International in Escondido, CA and said "here, make these look new again"
To be honest, since they specialize in Porsche, I know that they used a Porsche color but it's not as white as the original material was. It might have been something closer to a 356 or 911 color. Not 100% sure on that but it's a little more ivory in color than other pictures I have seen. Could be that in 45 years, it will sun bleach out perfectly white again though.
I will continue to look through my receipts and see if i can find anything.
@Mikey914 might be able to help you. I know that he's helped others with the white interiors.