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.
Quad QA12/P Amplifier - This is pretty close to Quads first amplifier. I got to put my hands on one of these once very cool early British amplifiers. http://www.itishifi.com