I restored mine. I used Evap Rust on the inside. I did a couple of applications and let it sit for days at a time. Evapo Rust is ok on the plastic. I also put a large chain in the tank and rotated for several hours. Between the Evapo Rust and the chain it came out great on the inside. I had to bondo a few dents on the outside, and then used Eastwood gas tank paint.