well,if it was poked through then you should be able to weld it as long as it was not weakened by rust from the inside.I would pull the tank and inspect it by looking in the ports or if you have a place local that can do it,Have it welded and hydrotested.You have enough energy in one of these thanks to kill someone standing or walking by the truck.I have seen what happens when a air tank has a semi controlled failure.Had a larger tank(around 20 gallons) blow the pipe off the end while running a machine.Compressed air has MASSIVE amounts of energy.Sent that 50Lbs tank shooting off like a rocket snapping the pair of 1/4" cables used to tie to to the machine.That was just the energy from a 1" hole.A failure from a rusted hole would release ALL the energy at once since it would tear and explode like a Grenade.So make sure the inside of the tank didn't rust out enough to allow debris to puncture the skin.Might look perfect from the outside but be a total basket case on the inside!
