I own a British-made Aeolian Weber upright Duo-Art of the electric-only
variety, type 60, built in 1923.

The accordion pneumatics draw their air supply from the regulated side
of the pedal supply valve-box.  I've recently discovered that this is
a very unusual arrangement, at least for a British instrument, and that
the supply usually comes from a port on the back of the expression box,
or a tee on the elbow of the supply to the pedals.

Does anyone else know of instruments with my layout, with regulated air
operating the accordions?  If so, was it generally considered a good or
bad idea?

My expression system seems to me to operate well, but I've little real
comparison!  Any thoughts would be appreciated.

Many thanks,
Jim Ridgewell (UK)