The radio section shouldn't see any power when off, only the clock would remain on and that doesn't have any circuitry.

Curious as to why you heat shrinked the capacitors....that COULD retain heat and possibly lead to early failure although that remains to be seen. All tube type devices require a warm up period to get them to function (except for some TVs from the early 70's which kept the picture tube filament slightly powered up)

Anthony