Hey Gary ~I have done it....all three ways: cleaned and sealed myself, taken it to a radiator shop to have it cleaned and sealed (red sealer), and finally, purchased a new one.
After all is said and done, I highly recommend the purchase of a new one, when available. You can try your best to clean it out and seal it, but chances of rust particles getting into the fuel system are high. Time + sealer + those chances don't outweight the cost of a new tank....imo
~ Victor
1941 3/4-Ton Pickup (in process). Read about it
in the DITY Gallery1955 Grumman Kurbside "Doughboy" 235/3 on tree w/ OD
1957 3100 - moved on
1959 C4500 Short Bus "Magic Bus" - moved on
1959 G3800 1 Ton Dually "Chief" - moved on
1958 C4400 Viking "Thor" ~
moved on to fellow Bolter 
