Don ~ You said exactly what I would have said, in greater detail. You apparently found the same stuff I did when you tried to Google(all questions, no answers). I didn't know about Rickenbacker, by the way; I did know about Leo Fender and Les Paul as major electric-guitar developers, but they both came after Charley Christian. (Maybe even after T-Bone Walker, too, for that matter.)

Melissa ~ Your single sentence is the only real information I've yet found. Can you elaborate, or tell us where you found the info so we learn more?