Make careful note of the order any shims are installed in.
*Don't need no steenking shims, it's ART*
Work over a towel on a bench so any dropped parts don't bounce and launch themselves onto the floor.
*No sense of adventure, EH?
Repairs go much faster without 15 minute searches for tiny screws.
*Only 15 minutes? Wuss!*
Once there is enough to grab, I would suggest make a carved hardwook piece (I have used parts of wooden clothes pegs) to put against the lens board.
Then bend or gently mallet with a hardwood dowel as the striker to bend or pound the lens board back until it is in line again.
Then re-asemble with care, and snug every thing up, and you are back in business.