[Arran]

By asking if it was electrically overhauled I was asking if someone had replaced every paper capacitors and out of tolerance resistor before you started using it. By your response I would say that the answer is a no. The reason I asked is that if the set has not been rebuilt electrically then it's very likely one (or more) of the 80+ year old capacitors decided to fail and that is the reason the set stopped working not the speaker. Speakers very seldom fail on their own accord, if there is an electrical problem with the speaker it is usually caused by something like a shorted filter capacitor burning out the field coil or the output transformer.
Regards
Arran