Back in '04 i bought some Mach 1 oem rolled tips. They came off a car with 50 miles on it so they looked new. I was debating welding them to my flowmaster cat-back but the inlet of the Mach tips is 2.25" and i have a 2.5" flowmaster kit, so i never did it.
Instead, i coated the tips with some light oil, wrapped them up nicely and put them in a box and sealed them up. In 30 years i'll toss em on Ebay!!