The cables you have are probably the older RG58 coax and most of the new systems uses RG6, but the RG58 will function as long as the run is short and they are in good condition. Many times the roof cable deteriorates so you have to pull a new cable through.
Tracing cables in these coaches is easy with the right tool. Your coach probably came with a VCR so you should have one cable that went to the VCR, one to the TV, one to the wet bay, one to the roof antenna which is routed through the booster, and possibly a cable to a roof mounted satellite dish.
I use an inexpensive Coax tester to trace the cables:
This coax tester is also avalable at Home Depot. It comes with 4 different color coded cable ends. You install one of these on the end of each cable: roof antenna cable, wet bay, TV, and what ever else you have. Then you connect the tester one by one to each cable inside your video cabinet and it tells you which color end it is connected to. Make notes and label each cable you test.
What roof antenna are you planning on using?