Well I would not have believed it unless personally witnessed.
As the o/c must be on the outer layer of the transformer, I stripped off the
cloth tape. There is indication that damp air has got in this unit but not
flooding or internal drips. But in the middle of this outer layer, with no
sign of corrosion or damp under the tape , generally, there is one spot of
blue green corrossion and a small break in the 0.9mm wire.
Maybe a spot of acidic something at that point on assembly and then years of
damp air. Bridging the break gives resistance of the winding of about 0.2
ohm.
Powering on a variac, could not take higher than 150V (saturating) so
assuming it is 110V transformer ( or problem on the original pimary ) output
read 4.7V ac , no load, for 110V ac input.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/