If it's the original style toggle switch, then the resistor is
wound on a hollow ceramic core then coated with a heat
resistant ceramic wash. Here is a series of pictures of one
that I rebult/restored for my 1950, 3604:
http://www.pbase.com/dennygraham/image/129207282 The hight temperature ceramic was a product that I got from
Sauereisen high temp. Cements,
http://www.sauereisen.com/ Without the ceramic coating the resistance wire will oxidize quickly.
Denny Graham
Sandwich, IL
