I am rebuilding an upright Steck American Duo-Art (the one with a
four-lobe pump and no pedals).  Most original tubing is missing.

There is a 3-position lever, marked "PP-MF-Concert".  "PP" opens
a two-tube pallet valve, and "MF" opens another one.  In "Concert"
position both valves are closed.  I need to know how I must connect
the four tubes of the pallet valves, to get the effect of "PP" or
"MF" and "Concert".

Another question.  The tracking device has an exhaust supply in the
bellows, and another one in the tracking cut-out block.  Where are
those separate supplies to be connected ?

Thanks for your reply.

Leonardo Forti
Rome