You can drill a small(1/16) hole in an inconspicuous location on the rear wall and insert a length of metal coat hanger, or other stiff wire to see how thick the wall is. With most coaches with a fiberglass end cap you may have quite a bit of depth.
If you have enough depth then you need to see where your cross members are. The cross members could be steel which might complicate things somewhat.
If you have the depth and want to recess the TV then all you need to do is cut the opening and install a frame on the inside to secure the TV. Once the hole is cut, it might be easier to run the electrical wires and antenna coax.
