[Arran]

Uh-oh. I hadn't thought about rubber coated wiring I just went though replacing some in a 39-30.

Fortunately Philco decided to opt out of using the rubber covered crap on the power transformer leads after 1939, or so they told me after I asked about the 39-116. The XXL (7A4) tubes are sort of interesting, Philco had an affinity for using either a twin triode mixer oscillator like an XXD (14AF7) or a pair of seperate triodes like the XXL for the mixer and oscillator rather then a pentagrid convertor like a 6SA7 or a octode convertor like a 7A8 in many of their 1941-42 sets. The 1939 116 uses a 6A8 convertor but has a tuned RF stage, the 1941 316 version has those twin XXL tubes and an extra IF stage.
One thing I have been meaning to do is restore both of my "Hippo" sets to stage a performance shootout as to which system works better, one has a tuned RF stage and the 7A8 converter, the other has a XXD (14AF7) twin triode mixer-oscillator but an extra IF amplifier stage. I suspect that the one with the extra RF stage may have the edge but I don't know for sure.
Regards
Arran