Welcome to TM forums MVP! I'm sure you will enjoy your new-to-you TM as much as we enjoy ours.
Just so you are aware, the thread you are referring to applies to a very old TM model that used a different method to adjust the torsion bars.
When you say you adjusted the arm on the torsion bar, I am assuming you meant that you loosened the 4 bolts at the bottom of the lift arm to raise the shell. I am also assuming that you checked that the distance from the lower edge of the box to the inside of the pocket stop is 39.5".
Do you feel any resistance at all when closing the shell, or does it seem to "free-fall"? Also, I know I previously PMed you with the following link:
https://www.trailmanorowners.com/for...ad.php?t=19939 . Did you check everything over I mentioned in that pdf article?
I'm sure others will chime in with ideas to check out as well. Good luck!