With a Jeep that old you may have some trouble findind a replacement tank. Is the one you have fixable, or is there even one there at all? By the time you find a replacement tank, and get it cleaned, and patched (if needed) you may be better off just looking into a brand new aftermarket tank. There are a lot of places that make them, and they come in just about any size you can think of. And it wouldn't need to be fixed or painted.