Dating fender twin ii reverb amps
The twill covering was first used in 1946 on the Dual Professional, a twin 10" 6L6-powered model of which only 400 were made before being renamed "the Super Amp" in 1948.These early models are referred to as "TV-Fronts" due to the shape of the cabinet when viewed from above.
However Superior Music has done a really good summary and here is a link to their website.
The first of these were the K&F models, produced between 19.
The early K&F and Fender amplifiers relied upon vacuum tube circuitry, with the company adding solid-state models in the late 1960s.
They are all very rare today and few have survived.
The first amplifiers made in-house by the Fender Electric Instrument Company have been dubbed the Woodie series, built in 1946 through 1948.
The type of face, grille cloth, type and number of speakers, type and number of knobs, etc.