Sorry that my Fender amp link was broken - I hate it when people update their web site structures !%*&*&*I will fix this weekend...
The new page is here:
http://www.fender.com/support/amplifiers.php
Note for your time period they refer to transformer codes...and have some info to date them:
Generally amps are much easier to date than guitars...there are more components that will have date related codes - this also helps whn determining how 'original' the amp is - many parts can be replaced over time.
Greta stuff is available including:
http://www.guitardaterproject.org/potcodereader.aspx
Dating any amp - source codes
http://www.schematicheaven.com/mods/datecodes.htm
http://www.provide.net/~cfh/pots.html (includes Jensen speakers)
Tubes, Capacitors, Transformers, Potentiometers (controls) & Resistors, and Speakers
http://www.triodeel.com/eiacode.htm
http://www.webervst.com/codes.html (note there are 4 pages of codes here) and more again at
http://www.webervst.com/morecode.html
Celestion speakers: Go to the drop down and go to "Chassis Date Secrets"
http://professional.celestion.com/guita ... /index.asp