Vintage Aero Supply Mfg. Co. aircraft fuel selector valve assembly, identified as PK-4 Fuel Control Selector Valve Assembly P/N 1039240. WWII-era aviation fuel system component with cast markings including “AERO 54021” and Patent No. 2164232. Heavy cast-metal 3-port selector valve assembly retaining its original capped ports, safety-wired hardware, and selector shaft components.

Assembly appears in 1944 "Aircraft Fuel Systems" as a PK-4 Fuel Control Selector Valve with 3/4" NPT ports. Screenshots of catalogue are included for reference; however, it is NOT INCLUDED WITH PURCHASE. The same catalog associates the valve with the Beechcraft JRC-1 / Model 18 family aircraft, though applications may have extended to other military or civilian aircraft fuel systems of the period.

The old storage wrapping included with the valve exhibits a handwritten “P51 fuel selector,” though no direct documentation confirming P-51 Mustang application has been located. Excellent display and restoration piece for warbird collectors, vintage aviation restorers, or military aircraft historians.