Your time queation. I work on radios as I have spare time or as the operation allows. I usually have a pile of chassis restored waiting for the cabinets to be done depending on weather. If I lacquer them it is done outside with a HVLP sprayer. I probably spent about two days or so on the OEM-7 if I put all of the times together that I worked on it. Since I prefer to work on 20’s radios the actual electronics often do not take as much time as the cleanup and cabinet repair/refinishing.
Rewinding the interstage transformers can take a lot of time. I can do a rewind in an hour but dissasembly, cleaning up the steel if needed, making a coil form and reassembly takes much more time. Sometimes I will use a Hammond 124A if it will fit in a can or 124C if the old steel will accept it. Unfortunately a lot of the old steel is 5/8" or 3/4" square and Hammond have chosen not to offer a coil that size so I rewind them to duplicate the original appearance.