He may say that JC was his first mentor, but I have found the truth.
On eBay is the amplifier on a cart true inspiration of Mr. Slagle. The text said it belongs to a 90 year old ham radio operator, so it clearly predates Dave's New York Noise work.
BROOK - Audio Ad Dec 1949 - Stop listening to DISTORTED MUSIC buy a Brook. Thanks for sending me this one Chris. Excellent. http://itishifi.blogspot.com