Hello.  My query of 101116 about theme levers elicited a number of
responses, and every one seemed to be describing a Half Duo-Art
different from mine.  I do appreciate all the advice and comments,
and believe that I have thanked all of my respondents.

I had heard that not all Half Duo-Art s are the same and now I'm
sure of it.  My Steck theme levers operate pallet valves that, on being
moved to the left, admit air to the pouches of the primary theme valves.
This, in turn connects the secondary theme pouches to vacuum, allowing
their glued-on pads to drop away from where they block access of full
vacuum to the bass or treble sides of the valve chest.

The Steck theme levers do not gradually uncover shaped apertures as
they are moved leftwards, allowing a gradual transition from reduced to
full vacuum.  It's a sudden death, "on" or "off" arrangement.  But that
doesn't matter, because my Steck is equipped with a Temponamic lever,
which enables the gradual transition.  My Stroud Metrostyle-Themodist
player does have the gradual transition mechanism, so I am familiar
with it.

After all this I'm fairly sure that I haven't made some major retubing
blunder.  However I have found a minor one.  I gather that on Half
Duo-Arts, the no. 2 (one eighth inch) accordion should be collapsed for
non-Duo-Art playing, so that the accompaniment vacuum level never drops
too low.  Somehow I've managed to have the no. 3 (quarter inch)
accordion collapse, instead, so that error needs to be rectified.

Now it's on to the next problem.

John Phillips in Hobart, Tasmania