it is proof tested to 500 psi
the gauge is at 150 psi, it sais "overfilled" (90-110 is the green zone)
the sticker on it sais it was last inspected in 1988(

so is it still safe to handle, and if so, what could i use it for?
i would like to make it into a pressure tank, but how could i refill it?
any input is greatly appreciated
EDIT:typo