I found this older thread which also discusses mounting a TV for the bed area of a 22R
In looking at the Drawing which Winnebago provided, I note that the dimensions are in millimeters; not inches. I see in View A that two vertical reinforcement strips are installed on the inside of the cabinet, but their location is vaguely defined.
Can you go to a local dealership to see where the TV mounts are located on another 22R? If you do a test drilling with a very small bit, you should be able to use wood putty to fill-in a "miss."
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