I owned that era RV for ten years when it was between twenty and thirty years old. I am positive it's actual market value is about $4000 max, probably more like $2500.
You will never get the dash A/C to work properly unless you replace the entire setup with new components for around 3-5K depending on who does it. Simply converting to the new chemical is a band-aid fix at best. The only place to get parts for the steering will be a junk yard.
It also probably burns twice that amount of oil, I personally would not take that RV for free.
Sorry for the bad news, just being honest, I hope I am wrong and others will chime in with a more positive outlook.
Best of luck