Bedroom slide out of line

[routemaster]

This Sunday replaced the "Clip on wiper outside and inside Bal-Acuu unit I had installed the "T" style wipes first time this was way too stiff to operate through the gap, so therefore I removed them.There is no clearance for the flip, hence this is why wipes were tearing up at top left and bottom right.
From what I see checking the box is within specs. Then it looks to me like the box is laying down, inside to the right. The jams look plumb allthough the roof decking to the header does have a run of at least 1/4" to as best as I can check,the rough sill either was welded in wrong or the weld has broken.
If welded with that run on the rough bottom sill should I shim up the roller or screw some Delirn strips to the under side of the outside floor to bring back the walls plumb?