I just picked up an aluminum 80 manufactured in 9-88 with a number 55432.
It's out of hydro. as of 04 and has orange paint over the last hydro date but had current vis. sticker on it and has air in it.
Does that orange paint mean it failed last hydro?
I only paid $20.00 for it so even if it is a paperweight I'll find something to do with it like make a lamp.
Many mark the last hydro so it's fast and easy to see. When cylinders fail hydro the dot is xxx'd out.