John Phillips mentioned that the wiring in his upright Duo-Art was
deteriorated and that the metal tube containing the wiring might not be
necessary with modern power wires.  I had the same thoughts but decided
that if some pump organs advertised "mouse proof pedals" there
might be a good reason to encase the wires from the early years.

While inspecting the wiring in my 1926 Duo-Art Weber I happened to feel
the metal tube containing the original wires.  It was quite warm from
some lengthy playing.  Later, while replacing the worn out "Off-On"
switch, I took a close look at the wires and found them to be turning
green.  Something (perhaps the rubber coating) had reacted to the copper
and caused it to be deteriorating.

I replaced the wires with heavy leads pushed through the original metal
tubes.  It eliminated the heat buildup.

Bill Chapman - in sunny but cool La Quinta, California

 [ Maybe sulfur ions from the rubber combined with the copper to make
 [ a green, conductive salt.  -- Robbie