Took the tank out and power washed the outside. The tank is resistance welded at the seam. Tank looked good on the outside, still in the stock JD green, no corrosion that you can see from the outside. Did a preliminary clean with Purple Power and got a lot of scuzz out of the tank: brown paste, corn flake sized rust flakes, a couple of sticks of wood the size of a tongue depressor. Not leaking from the seams...but 11 tiny pin hole leaks on the bottom surrounding the drain boss, and one on the drain boss weld seam. Plan on soldering the tank on the outside over the pin holes and drain boss and then doing a fiberglass tank repair over the bottom of the whole tank, plus the KBS kit I ordered the other day for sealing the inside. The fuel pickup that goes into the tank has a stand pipe that picks up fuel about 2" up from the bottom of the tank so you don't get water and crud into the fuel line...good thing. Bad thing, there's no way to drain off the water that ends up in the bottom of the tank without taking the tank out or siphoning the bottom. My tank will hold approximately one gallon (estimating) of sediment/crud and water at the bottom of the tank. 40 years of water eating away at the tank bottom.