One version of the 71 FJ40 fuel tank is still available through the dealer system. FYI, I've got two of them new in the box for my future use. It's the type that's designed for FJ40s without the vapor cannister system. Part number of the tank is 77100-60012. Rubber tank cushions which are a big improvement over the moisture attracting fabric originals is 77651-60030, and it takes three. Fuel sending unit rubber gasket is 83361-20030.
You're probably better off ordering through your local Toyota dealer that gives TLCA member discounts, as ordering one elsewhere and having it shipped will probably run more than your local price. Personally, I wouldn't mess with installing a used tank, as it may have rust particles (at a minimum) which could get in lines, or, maybe even have leaks. I've never seen a new OEM tank leak once installed.
