Bender, you are going in the right direction. As for the slot in the mount not aligning with a stud on one side-use a 3/16 toggle bolt there and you will be fine. On your tv pick it up and you will probably find that one side is a bit heavier than the other. Make the heaviest side align with the stud if possible. If that puts it out of wack for your viewing, at 39 lbs. I don't think you would have a problem with the toggles even if they weren't through studs. Always drill through sheetrock even if not on a stud. I have seen people use a screwdriver to punch holes in the walls for the toggles and blow the back side of the sheetrock out, making it weak. Good luck.