If/When installing new seat belts, ensure to NOT mount then to the wall.
TMC motorhomes with a garage mount the bench/bunks to a light piece of sheet steel inside the vacuum bonded wall. The rest of the wall, except for the aluminum frame, is foam/fiberglass/finished interior board.
Only the floor would have the strength to act as a seatbelt mount.
Interestingly, Thor is sometimes putting only 2 seat belts in their dinettes...ours came with 4 there (2 front facing/2 rear). I think there is room for 4 in the average dinette, and the ride there would be better than the garage.
Congrats on the 29H...I think those are very nice and versatile RV's.
And...just because the 29H is not a Class A, there is no reason not to visit and say "Hey!" here:
http://www.irv2.com/forums/f120/i-lo...aw-102560.html
Safe travels