One has to wonder where all those factory original export back panels are! Another interesting tidbit is that a lot of Fenders were imported into Australia in the late 1950s and early 1960s that were stock 110-volt (domestic US) units.The Australian Fender Distributor then installed 240V - 110V stepdown transformers in the bottom of the cabinets.I remember two 'suits' from upstairs standing behind me occasionally doing time studies.They actually held clipboards and stopwatches to measure how long it took for me to attach various parts.
Well, this universal “truth” was debunked when we found a bunch of amps with transformers made by the Better Coil and Transformers company.
These units look, and apparently sound, just like the Schumacher-made units so it’s easy to overlook that “831” code.
Working at FMI – I was able to interview a fellow (who wishes to remain anonymous) who worked at Fender in 1972-73 in the amp department.
Also note the vertical black lines on the control panel (found on earliest silverface amps) and the large ceramic power resistors coming off the power tube sockets which indicates the AB568 circuit. But really, these cabs were large because they were of a “special design” that “greatly improves tone and volume without distortion, and permits optimum performance of the speakers.” At least that’s the reason according to the ’69 catalog.
Also, another thing I’ve never seen before is a what appears to be a shipping tag of some sort (see photo).