Hello MMD.  This afternoon I dismantled the primary theme valve box
that sits on the top of the main plank in my 1919 Steck Duo-Art
upright, near the bass end.  The two primary theme valves have travels
of 0.025" and 0.029", respectively.  I think these measurements are too
small, and I propose to set both valves to a travel of 0.035", unless
somebody tells me that that's a bad idea.

My notes from my rebuild of my Half Duo-Art upright Steck tell that
I used that travel for its primary theme valves, and they seem to be
doing the required job.

John Phillips - in Hobart, Tasmania