Find the sticker, check for backer, and mount.
I have found the sticker to be off the mark on a few models.
The walls are thin enough to tap on them to get a good idea of where the wood filler is located.
I got lucky and found some posts on the owners forums where owners addressed this more specifically.
What some have done is to use a piece of plywood (maybe approx 12x12)
and mount that to the wall near the OEM sticker with a lot of screws with spacers. This holds the plywood away from the wall so you get a nut and bolt tightened to hold the tv mount to it.
The weight of the tv won't rip the bolts out of the 12x12 plywood and all those screws offer a lot of holding power opposed to 3 or 4 .
when traveling...use a strap to secure it. if you use one strap, run it horizontal. Two might be better on a 42" , then I would run them vertically at the 25% and 75% mark.
Am I making any sense ? :h :)