A bladder tank doesn't care what position it's in with respect to it's paint job etc.
Once a bladder tears, ruptures, splits or just breaks, the water/air separation is gone. The well water is deficient of oxygen so each cycle it steals a little more air from the tank until it becomes waterlogged. Another thing that happens with a broken bladder. The water starts getting on top of the rubber. The rubber gets across the outlet/inlet and prevents the water from leaving the tank. Each cycle the tank fills up a little more while the air is taken out and pretty soon you have a tank full of water with no air left cycling it's heart out. Not to mention the nasties already mentioned. Remember, the inside of the tank is not painted or treated in any way. It's just bare metal.
The tanks with replaceable bladders were made that way because the bladders were junk in the first place. I changed one bladder in a Con-Aire tank many years ago. I will never do it again. What a mess.
I think you see that the general consensus here is to change the tank. I recommend either Flexcon or Well X Trol. The only two tanks on the market as far as I'm concerned.