Found a CTC5 Aldrich (sorta)

[Eric H]

Originally Posted by Telecruiser

I suspect he real reason it was changed is the insulator used for the metal tube had a very bad habit of breaking down and would start arcing at some very inconvenient time.

Just curious, were your folks smokers?

Tobacco soot + high voltage can really collect dust in a hurry (we've all seen what smokers sets look like inside!) so if they were that might account for the frequent problems.