Dear MMDers,  I agree that the best policy is to replace any wiring.
Most pneumatic instruments do not have very much and a lot of it is
hidden anyway.  With a little searching, suitable substitutes can be
found for most types of wire using modern materials.

As an example, one type of wire that can sometimes be noticeable in a
coin operated instrument is the wiring for the lamps.  This was a cloth
braided type, you know, the old fashioned kind that used to fray ? I have
located a local lamp shop that does lamp repairs and they carry several
types of this stuff and will sell it by the foot.  It makes a very
appropriate substitute for the old style cloth covered wire.  I wouldn't
use this for the line cord (mains wiring) but it works very well for the
lighting circuits behind that stained glass.

Bottom line suggestion: check your telephone directory Yellow Pages for
someone who repairs old lamps.  They will often have a variety of stuff
that can be used to upgrade the wiring in your electrically operated
instrument.

Bob Conant