'70 Duster Vinyl Top Question

For a full vinyl top, most places show a 36 or a 41" center width. The guy I ordered it from shows only one choice ("regular seam").
It came in yesterday and it's 41". BTW the VT on my car was gone when I got it so I don't know if it was 36 or 41 originally.
My concern with this is that the top was made with a LOT of extra material. There is probably a foot extra all around. I don't know why they would waste that much material so I'm wondering if maybe this top is for a bigger car ???
The guy I bought it from seems like a good guy and I asked him to check on it for me, but I wanted a 2nd opinion from you guys too. Thanks !!