Hydraulic Pressure Gauge, 75 PSI
Here is a aircraft Hydraulic Pressure Gauge, 0-75 PSI, made by US Gauge, part number 61349-AW-1 7/8-17BP3F7. The design of the case is vintage 1940-1950's.
It is in exceptional condition. The glass and case are intact and the markings are clear. Measures 2.25 inches diameter and ~2 inches deep.