It had two twenty four hour soaks in lacquer thinner to remove the gas tar layer. Yesterday I diluted muratic acid closely monitored, flushed with water, then flushed twice with baking soda and water. Last I flushed it with pb blaster to prevent rusting. It still has some rust flakes floating around which is next to impossible to get them all. So I made a jig to attach to the gas cap. Little bit of chain, JB weld and a smoke detector magnet i had laying around to help along the cleanup.