[Arran]

The only electrical weak point in some pre war Northern Electrics seems to be the power transformers, every other AC N.E I have run into seems to have a Hammond replacement. I don't see many N.Es where I am, except the post war 5000 series models, I have a chassis for one downstairs that was a clone of an American Bosch. The other problems are Tennite plastic knobs, oddly similar to those used on some Silvertone sets, and washaway paint on some dials, at least in the 1936-37 models. If the back from the Mirrorphonic Chamber was missing, you can still buy that pressed wood pulp material in some lumberyards, sold as sound deadening board I think, back when the N.E was made it was known as "Ten Test" or "Donacona" board. That stuff used to be popular as wall board, in the 1930s and 40s, before drywall became common, they had a type of drywall but it was in 12'' wide strips and had to be plastered over.
Regards
Arran