[Arran]

 Don't try stripping that escutcheon Fred, it has a faux finish on top of it, just clean it with Gojo, touch it up, and maybe clear coat over it with lacquer if you need to, not sure about the one for the pushbuttons. I don't know what to suggest with the Marconi decal, I'm not sure if Radio Daze carries those or not, I'm guessing that they don't and I don't know who else would make them. You may have to strip around it very carefully if you want to preserve it, then lightly sand it and clear coat over it.
With regard to the electrical end, these sets usually have a pair of bias cells under the chassis, so you may have to figure out a substitute, or make circuit modifications to get that extra -1.5 volt bias. I'm not sure about this model but I have a Marconi model 157, and it has some rubber wiring, including on the power transformer. The speaker was made by Utah I believe, in spite of the decal, Marconi did not manufacture their own speakers, neither did Rogers for that matter.
Regards
Arran