You say you have looked for a "proper" answer but the fact is that the rules don't cover every possible situation and you are expected to rely on airmanship and training.
Bottom line is that, as the aircraft commander, you take what steps you consider necessary to ensure the safety of your aircraft. I'd certainly say Squawk 7600 (or even 7700 if weather is bad and you feel you are in urgent need of help). Either will get their attention (if they see you) and then maintain VMC and fly either to the overhead or to the runway and land. Keep a good lookout and, if you see other traffic keep away. Can't think of much else.
I fly an old aeroplane with just one radio and I always carry a hand-held with a jump lead to plug my headset into that. Might be worth considering the same thing?!?
Happy Christmas!!
3 Point