phone or email Dutchmen and ask for a diagram of that wall section. I bought a Heartland Fuel 352 and called and they emailed me a factory sheet that shows dimensions and how the wall is built. Since yours is above where the "factory" location is for a TV, they should supply you with drawings showing the stud locations. For mine I cut a piece of 1-1/4" thick board a little bigger than the TV wall mount. I mounted the board to the factory TV backing in the wall (which ws smaller than the TV wall mount). Then I mounted the TV wall mount to my mounted board.
1996 Itasca Suncruiser 34RQ, P32 w/ 454 TBI, Banks Air Intake, Harris Towmaster Performance Chip pulling a 2012 Jeep Wrangler Unlimited.