No disrespect, but you are a couple of decades older than I (DOB 1937),
and they don't use varnish anymore, they use epoxy to hold the windings
together.

Bill..Most of the stuff I have had failures on lately had nothing on
them. ((DOB) 1927

Many modern motors use bondable wire. An adhesive resin is applied
to the magnet wire at the manufacturer. After winding the wires are
heated and the wires are bonded to each other. This eliminates the
need to apply a varnish, epoxy, resin, etc., and also eliminates the
cure cycle for these materials.

John Normile