[MrFixr55]

I can dream too. Even a broken clock (or a broken MrFixr) is correct twice a day (in the US, since Europe uses 24 hr format, the broken clock and broken MrFixr is correct only once a day.

I think that fixing the low screen voltage will go a long way in increasing performance of the set. Often, sets that I repair work well without an alignment or only a slight "peaking"

Adding a radio / Aux switch should be easy, as the set was literally designed for it. Your set was built before the "RCA" jack and plug, which were introduced ca 1941, but the terminal strip on the back of your set was standard on many RCA sets, even dating back to the 1932 R7A. There may be a sticker stating that the radio will make a fine phonograph with the RCA Model Something-or-other phono attachment. The radio / phono switch was on this Phono attachment. RCA built an adaptor which screwed on the back of the cabinet and either attached to the terminal strip on the back of the radio or was "wired in". The only inconvenience was that the switch was on the back of the cabinet. I have a 1941 RCA 16T2 that has the RCA jack and radio-phono switch on the rear apron, from the factory. My 1941 RCA 14BT2, a battery farm set also had the jack, but no switch. One tuned the radio to a quiet zone on the band. My 1948 RCA 1R81 "Livingston" AM / FM set has a phono position on the band switch.

Since adding a phono switch was a common accessory or mod back in the day, doing the same with period parts is legitimate. All you need to do is make a plate that will fit the corner of the back of the cabinet and add a jack and switch to that plate and connect the 3 conductors (signal in from radio circuit, signal out to amp and common ground) to the existing terminal strip.

Hope this helps.