Help determining tank size & LP vs HP

[Scared Silly]

You already have the most important info but here is the complete run down

IOL - actually ICC (Interstate Commerce Commission - now DOT)

3AA - Steel (3AL - Aluminum)

2250 - working pressure in psi

HJ144212 - serial number, probably made by Norris.

3 67+ - first hydro, with the plus can be filled to 2475 to get a full 72 cuft

 

[Hatul]

It's a very old tank that hasn't been used at least since 81 and who knows what's inside now. If you buy it at least make the sale conditional on it passing the hydro and vis.

Adam