62 Lancer gas tank

thanks for the reply. Ive read a ton of posts on gas tanks. But I did not see one definitive answer on the type of material used for between the strap and tank and the mat on top of the tank. some even say not to use anything. I was told roofing felt was close to factory material(will that trap moisture?) a lot of people advise using old inner tube rubber, but i would think that would definitely trap moisture.. i finished cutting and drilling new mount holes, everything fits great i just need to figure this out to be finished.
thanks for any help