Manning, Maxwell, & Moore
Engine Gage Unit for US Army Air Force Fighters, 1942, Type B-7, AN-5774-B
The US Army Type B-7 Engine Gage Unit was used across a variety of aircraft of the US Army Air Force during WWII. In particular, the B-7 made by Manning, Maxwell, and Moore part number 6548-73-15 was used in fighters P-38 Lightning, P-39 Airacobra, P-40 Warhawk, P-47 Thunderbolt, and P-51 Mustang, according to the US Army Air Force's Maintenance Interchangeability Cross Reference Chart dated Dec1943. This example is marked AF USARMY on its face and had a serial number prefix of AF-42, evidence of a manufacturing year of 1942.