I need one of the ceramic insulators that keep the heating element from touching the frame

HVAC 1000 replied in 2009:

"You probably will not be able to locate parts for the old Wesco. There has been many posts here and on other boards about this problem. I have searched all over for parts and none are available. They also used a special ribbon type heating element so the standard replacements available for other brands will not work either. If you ever find a place that has the parts please post the company and phone number because folks doing a Google search or other search will be glad to know they are available.

Only real option is to replace the unit. Sorry "

That said, an insulator is a pretty generic item, it just has to keep the element from grounding I bet you could find a similar one and figure out how to adapt. Go to a good HVAC or electrical supply store and see what you can find.