I remember two 'suits' from upstairs standing behind me occasionally doing time studies.
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).
These are marked with EIA code “606” which is the company number for Schumacher.
Well, this universal “truth” was debunked when we found a bunch of amps with transformers made by the Better Coil and Transformers company.
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.