I just mounted a 32-inch LCD above the fireplace in my Landmark RV. Actually it was an easy conversion still using the built-in pullout/swivel.
Attached 2 right angle braces (study onces) at either side to a piece of 3/4 plywood.
Attached an inexpensive non-swivel non- tilt wall mount and presto - done deal. Great thing is that I then had room behind the TV for two DVD shelves that I I built and then attached the stereo/sound receiver to the top of that. Satellite receiver now has it's own place in the cabinet hole below. Very neat installation with minimal cost and works better than custom fit.
Only requirement is to measure things correctly.n Can provide detailed instructions if any of this is unclear.