Yes the heater one dropped 50 ohms or so and then rattled rapidly up to more
than 150K with continued heating from a soldering iron.

So I've learnt something else today.

Now just to discover the source of manure smells off kit.
Currently orking on a Fender Pro 185 from 1989 and the workshop has a
noticeable smell of manure. On poking my nose directly over caps,
transformer, cabinet (for fish glue or something) etc I cannot localise it.
I looked at another of this exact same model a few months ago and no such
smell.
A year ago I repaired a JBL domestic amp from the 1960s and that had a very
strong , even stronger, manure smell, but again could not localise the
smell.
With reservations about breaking the "special relationship" one common
factor is they were both made in the USA.

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