I was browsing a local antique mall last weekend and happened across a 1928 Crosley model 706 Showbox and RCA Radiola 100 speaker. The pair were on sale for $60. The price was right and 20 minutes later both were in my trunk heading home. The Showbox was in great shape, with no pot metal rot in the tuning capacitor tank, dial drive gear, or all the other usual places for radios of this era.
The radio was missing a 71a output tube and the Mershon filter capacitor was long gone, replaced by a 1940's era Mallory electrolytic can mounted to a custom made circular steel plate. A neatly done repair made at some point in the past, The Mallory had also shorted from age. I replaced the filter with two new 10uf 450v electrolytics, and the other metal cased 2-5uf oil filled? caps with electrolytics of similar values, leaving the original parts disconnected but still in place. With a new 71a, 2 meg resistor replacing the grid leak, and a 75ft antenna, the set plays great.
The Radiola speaker needed a couple of patches to the cone which I made with cigarette rolling papers and diluted white glue, from behind, in order to hide the repair as best I could.
One thing I learned from this project, the 71a and other early directly heated triodes are freaking expensive!