[Arran]

I don't know much about a Radiola 46 but I own a Radiola 44 and they used a type of pot metal in the tuning chassis, but most don't disintegatrate so much as warp causing the plates to rub. The good news in the case of the Radiola 44 is that the stators are in seperate sections so you can move each section to cure the rubbing plates. It isn't an outstanding radio but not a bad one, it is only a TRF while other RCA sets were Superhets but TRFs can perform reasonably well onec everything is set up right.
One set I have heard of being a dog is a Radiola 33, they were a budget model with a steel cabinet, a true 1920s art deco steel cabinet, I have the matching speaker to a 33. If you can find one in good shape that's fine but the steel cabinet had pot metal corners which sometimes broke, and the steel panels had a faux woodgrain that is often worn off.
Regards
Arran