[Arran]

With regard to the 25 cycle transformers they can take the full 120-125 AC line voltage without complaint and can normally take more overloading then their 60 cycle siblings in the same models. This is part of the reason why I am using a 25 cycle transformer as a replacement in a C.G.E model KL500 set that had a 60 cycle one with a shorted high voltage winding, it actually came out of a Stromberg Carlson I think but it fits the hole and is close in voltage output. I guess to run a transformer off of 25 cycles you had to make it tougher and more resistant to core saturation, hence the substantially larger quantity of iron.
This is a bit off topic but with regard to the Rogers Eleven -66, did they move the tuning light from the center of the dial pointer to that green plastic lens above the control panel? I think it's strange that a 1937 model would use the same dial scale as a 1936, many of the 1937 models had an airplane dial with a different graphic design where they moved away from the flowery "Rogers" script above the center of the dial and went with more modern looking block letters fitted vertically into that wedge shaped area at the bottom of the dial. I noticed that they did change the cabinet, the console version of my Ten-60 had six short legs rather then a full length cabinet.
Regards
Arran