That is most likely a steel 72.
US Divers is now Aqua Lung. It was not the tank manufacturer… the tank was just rebranded by US Divers. US Diver had the tank built for resale. I own about 1/2 dozen steel 72 that are stamped US Divers. I also have a couple of Voit tanks... neither built their own tanks.
Based on the stamping I can’t tell who was the actual manufacturer of the tank, but I would guess maybe WalterKiddey (sp?), maybe a PST (Pressed Steel Tank). The serial number doesn’t look like a Norris tank.
The: (L IN CIRCLE) is the original hydro tester symbol and I can probably look up who the hydro tester was and the original manufacturer, but you don’t really need that information.
The tank was first hydroed in 10/65 and at the time it was + stamped giving it a 10% over fill allowance.
The ICC means Interstate Commerce Commission. The ICC stamping has now been replaced by DOT (Department of Transportation), but there is no difference to the hydro facility. Both stamps are equivalent.
The 3AA is the DOT specification for seamless chrome-molybdenum steel tanks. The code for that tank is the same as for most new LP tanks built to this day. With the 3AA and the working pressure is all the information the hydro facility needs to do a hydro.
The working pressure is the 2250 (that is in psi).
Having the tank hydro tested and put back in service is not a problem.
Good luck