Problem with the powdercoat process is the sandblasting. That sand gets everywhere, you'll never get it all out.
Have heard some horror stories of otherwise beautiful restorations that ruin engines due to oil tank sand. To me
same would apply to fuel tanks, sanblasting effectively ruins them (although they look good cosmetically).
Several vendors offer reconditioned oil tanks; also Norvil lists new ones at (seems to me) reasonable prices,
with the exchange rate in favor to USA. cheers