Why do you assume the parts are all "factory original"
From your description I would
tend to think that the original transformer failed and was replaced by the triad xfmr.
Who ever installed the replacement must have juggled parts to get the voltages closer to
original values. Since the electrolytics have been changed to non-original types, this
bolsters the notion that considerable work has been done on this receiver using non original
parts. Bat handle toggle switches can be found at various wholesale houses or cheap at
swap meets, just a matter of searching. Power transformers are becoming more rare and
finding an exact replacement is a problem. However a few volts difference one way or the
other shouldn't present a problem. The multi-switch is a different story.