Gas cap seal repair?

[sfm5s081]

So in my quest to be the 1965 gas cap expert, I have come to yet another stump point! I have an original gas cap with correct stamping and tether. However; the original paper seals have shrunk and the brass spring doesn't have too much spring. Is there a solution to make the original gas cap fit flush on the car like it is supposed to? As in not having to break down and buy a repo?

Thanks

[sfm5s081]

The best repair is to buy a new one from Brant at VA Classic Mustang

http://www.virginiaclassicmustang.com/65-GAS-CAP-P2080.aspx

[gt350hr]

    I have done it but it is a tedious job. "Manipulating" the new paper gasket requires wetting it to get it past the bumps and drying with a heat gun to dry and shrink it back to size. Unless you are in a judged show , Bran'ts is the way to go!
     Randy