These say "Fender Electric Instruments." Depending on the model the use of these pre-CBS panels have been observed on amps as late as August 1965, except for Champs and Vibro Champs which had foil stickers on the back the chassis.

The biggest tip off would be the control panels which brings us to interesting factoid #2.

After CBS bought Fender in January 1965, there were still plenty of control panels for various models that were in stock.

Dating Fender Tube Amps by Serial Number, Part I by Greg Gagliano Copyright 1997, 20th Century Guitar Magazine. Well, we'll get to good parts, but first a little background information is in order.

After reading Teagle and Sprung's excellent Fender amp book, I took them up on their challenge that maybe someday someone will compile enough serial numbers so that Fender amps can be dated that way. I contacted several Fenders collectors and dealers who were kind enough to supply me with data.

Likewise, the brown/blonde Tremolux, Concert, Vibrasonic, Twin, Pro, Super, Vibrolux, Showman, Dual Showman, and Bandmaster used a sequential numbering independent of model, but as with Fender guitars, these were not used consecutively. The 1956 to 1963 Champ, Harvard, Princeton, Deluxe; the 1956 to 1960 Vibrolux, the 1956 to 1964 Bassman, and all the tube reverb units have their own serialization scheme.

The Champ has a "C" prefix, the Harvard an "H" prefix, the Princeton a "P" prefix, the Vibrolux a "F" prefix, and the Deluxe a "D" prefix.

His particular area of expertise is in Fender amps made from about 1960 through 1967.

Devin runs Doc's Music in Springfield, Missouri and his interest lies in the woodie and tweed Fender amps made from 1946 through 1960.

I turned to the Internet to do some more networking which resulted in a major turn of events as I met two individuals who have become instrumental partners in this project: Greg Huntington and Devin Riebe.