Boost Pressure Indicator, MK IIIm, 6A/1581, British Royal Air Force, 1943

Here is a WW2-era Boost Pressure Gauge, -7 to 25 PSI, used to indicate the supercharger power being delivered to the engine when demanded. Used in Merlin-powered RAF, RAAF, and RCAF aircraft. According to the RAAF 346 Types and Locations of Instruments in RAAF dated 1945, the 6A/1581 appeared in the DeHavilland Mosquito.  This is New Old Stock in its original box dated 1943.  Mint condition gauge.