Manhandled this thing in from the shed today.

[Electronic M]

If you have a dimmer switch that can sometimes be used as a poor man's variac....YMMV

Unless it it has a removable metal hatch under the chassis (Zenith was known for having those, but I don't know about GE) you WILL have to REMOVE the chassis to work on it....

If it is old enough you might be able to get a cheap sam's from a re-seller for it IF you can find the correct sam's number for the chassis. Another way to get cheap sam's is to find a library that has them and make a photocopy....Libraries at older technical schools/community colleges, and main branches in major cities often have them.