Oil Quantity Indicator, C-54, R5D, Douglas Skymaster, Bendix 6007-58A
Here is an Oil Quantity Indicator, Bendix part number 6007-58A-15-B, as illustrated on in the US Army Air Force's Flight Manual, dated January 1945, for the Douglas C-54 Skymaster Transport (see photo). Appearing on the co-pilots panel, it is marked for engines 1 &2. Measures 3.25in diameter and ~6in deep. The scale contains markings in the US Navy style color Munsell Green, so it may have been used in the USN's R5D transport.