Seems fine, the bloke selling had had a few Fantics over the years and was going back to twinshock Moto-X
He has a car paint shop, so he sealed the tank on the inside and then painted with proper plastic paint on the outside, so we'll see
If not i'll look for a decent s/hand tank or buy a new one from Classic Trials, not a showstopper
Rest of the bike seems fine