[tinkirk]

I've got a 29 now that the tank was filled up before parking it in 1965! tried Acetone and that kind of worked but the fumes are not nice, started putting a couple gals of E-85 gas (if you want to call it that) shook the car as hard as i could, stuck an air hose in the tank and bubbled it and, drained it out the bottom had to take the valve out the bottom and install a hose to it so i could blow air backward to open the hose up before draining it,did that once a day for about a week, pretty much took care of the problem still have a little more cleaning to do but at least i was able to put gas in and get the motor back running again

Good Luck on how ever you decide to take care of the problem
Terry