A little boring history, these fuel selector valve and strainer assemblies were originally manufactured by Airborne Mechanisms in Cleveland, Ohio.
Shaw Aero Devices here in Naples purchased the rights; subsequently Parker Hannifin bought Shaw Aero Devices in 2007. I was contacted by Shaw a couple years ago when there were having difficulty with their new Twin Comanche valve; I assisted in a small way.
When I asked in turn for a “favor“, regarding the parts breakdown on the 400 valve to possibly have replacement parts available, guess where that went.
Parker [Shaw] manufactures the new SS valves for the twins; they make no mention of the 400 valve – I tried.