Hello, I have just bought a 1979 cb550f in need of a full restoration. I am doing a bit at a time and at the moment I am concentrating on the petrol tank which looks not to bad from outside but inside it is brown with rust, so much so the carbs are also full of powdered rust that has got past the fuel filter, so the carbs will need to be re built later. I would like to buy a brand new tank but I am told they are discontinued, I wondered if there are any companies out there that make reproduction tanks or if all else fails I could use one of the many tank repair products out there, which product is best?