I just finished my Marconi 156. I guess you would say I repaired it rather than restored it.
As received, it had a bad power transformer. Since I am in Utah, it is unlikely I would ever find a parts radio. I tracked a Stancor transformer with the correct footprint, voltages, and current. All caps were replaced – not restuffed. All brittle wire was replaced. A fuse added for safety along with a polarized power cord.
Do I still have an 80-year old radio? It likely plays as well as it did the day it was manufactured. I am confident that it will safely play for many more years now. 🙂