I have acquired a Standard action piano.  Unfortunately the motor
governor was completely destroyed.  I am trying to rebuild it, but
I have no idea what the original "span" was.

I tried 2.5 inches but the fold in the cloth comes into contact with
the adjusting screw, and/or the felt "stop" bushing.  Apparently there
were different types used, as I have another Standard, but the governor
is not the same one.  Do I use the "trial and error" method, or can
someone help me out?

Thanks,
Gerry Ceccarini