The antenna on the left looks a lot like the CB radio antenna on my '67 Airstream. You can read more about what I did here
The dangling wire on the right looks like 300 ohm flatlead wire commonly used for television in the sixties. I tried installing balun transformers on both ends of it to convert to campground's 75 coax, but lost a lot of signal strength. So I ran a new coax wire to the back of the coach (just like you're thinking).
FWIW, I have a somewhat original rockguard installed that still looks nice. But if it were to break tomorrow, I doubt it would be replaced. New, flat glass or Lexan is not that expensive (compared to a rockguard), and I don't think the appearance of a rockguard is necessarily an improvement to my Overlander's look.