I don't have any art-deco trucks, but I have 7 GMCs with tanks behind the seat. I buy repop tanks out of Canada and that is the end of it. I have run over the road trucks for over 45 years. I have used aluminum tanks for over 30 years. Steel tanks with Diesel will drive a person crazy with rust. Ryder used to spec some trucks with steel tanks, but they got rid of them before they were 5 years old. Just about the time the rust got bad and then it was someone else's worry.