Hello,  More oddities concerning my 1923 British-built upright Weber
Duo-Art.  The single-valve chest attached to the electric switch
pneumatic has two suction output nipples coming from it, directly
connected to the suction input, presumably to feed something else.

Also, on top of this valve chest is a pallet-valve which is operated
by a finger attached to the moving pneumatic board, such that when the
pneumatic closes and switches off the power, the pallet valve opens and
remains open.  Any ideas?

Finally, the right-hand pipe connector, behind the wind-motor, has
five connections through it rather than the four I've seen in schematic
diagrams.  Perhaps these differences are linked in some way?

Photos are available.  Many thanks in advance for any thoughts,

Jim Ridgewell