..You wrote, "my Kyotronic has a company called 'Kyosel' on the label. The name must have changed to 'Kyocera' at some point thereafter. The real expert on this subject is Evan...."
Well, at least you got that last part correct. :)
Kyosel isn't a company. It is a common Japanese word that means "harmony" or something along those lines.
The name "Kyocera" is a portmanteau of "Kyoto Cermanics" .... same deal with "Toshiba" which stemmed from "Tokyo Shibaura". Both part of the Japanese trend to Westernize their names in the late 1970s and early 1980s.