Oil Pressure Gauge Set, Dual Engine, for 4 Engine Aircraft, US Gauge Type B-9C C-45 The case may have been

The case may have been exchanged with the dial

Here is an article from Flight Magazine Sept 1943 describing the Astrograph

Here's a helpful video on the Astrograph from a fellow enthusiast

Above this altitude an A-13A or A-14 oxygen mask were used

According to the Maintenance Interchangeability gude dated Feb 1945

Oil Pressure Gauge Set, Dual Engine, for 4 Engine Aircraft, US Gauge Type B-9C C-45 The case may have beenThis is a pair of 1940 50's vintage dual engine Oil Pressure Gages, type B 9C (formerly AN5772 2) and made by US Gauge., labeled for engines #1 & #2 and 3 and #4. Likely used in late WW2 or post WW2 4 engine aircraft such as B 29, B 50, C 54 etc. Do your own research to confirm. The instruments are in very nice condition for their age. The dial markings are clear and the glass and cases are intact. Both have been painted on the outside glass with the