My "go to" place for oddball or obsolete electrical parts is Todd's Auto Parts in Nashville Tennessee. They have been in business since the early 1950's and they have an electrical rebuilding shop with a huge inventory of NOS parts. The Cumberland river flooded their shop a few years back, and I don't know if any of the inventory got damaged, but at one time they were the place to call in the southeastern USA for older electrical parts.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!