Are Reynolds Bb/Eb Valves Interchangeable?

[Z-Tuba Dude]

Hi,

I Have a Reynolds 4 valve Eb sousaphone, but the 2nd valve was changed out for another makers' valve. I works, *ALMOST*. I think that Reynolds Eb horns are fairly scarce, but Bbs seem to be more prevalent.

My question: If I were to aquire a Bb 2nd valve, would it work as a substitute?