Oxygen Regulator Type A-9A

We believe this instrument to be a cockpit mounted oxygen regulator for use with the A-8B oxygen mask. It was purchased from a source in Australia and we were told they were fitted used in the P-40 Warhawk fighter of Flying Tigers fame as well as on the the B –17 Flying Fortress and the B-24. It appears In excellent issued condition condition and the data plate on reverse confirming it was made by Bendix of New Jersey against serial nos AC-41 109491. The dial of the instrument is 2 1/2" diameter (6 cm) and is dual metered indicating both "FLOW" and system "CYLINDER PRESSURES" with two independent needles.