The Bulb(12v3.4w,stanley,a72a) is the most widely applied product in the GS750EN 1978 (C) USA (E03) SPEEDOMETER - TACHOMETER (GS750B) ( nine times ).
Check out any of the thirty Speedometer - Tachometer (gs750b) components enlisted.
Some items from this specific schematic: Washer, Speedometer Assembly, Socket,meter, Nut.