HP air tank - Need info

[wadester13]

I have an old oxygen bottle that I have painted white. It is rated at 3360 psi hydro-test. Do I need it tested/inspected to use in my sub, it will not be used to scuba and annotated as being "not suitable for breathing" (the test is probably out of date)? Could someone recommend a tank mounted regulator, used would be ok, that I can use and at what pressure, to blow about 1.5 cubic foot in about 2-3 seconds using 1/8 to 1/4 piping, needle valves can be used if needed? It is a DOT 3AA1015. 5" X 14". I will also be using this to power my masts and antenni using needle valves.

Thanks,
Brian