Anyone have any idea on how they handled this?
I'm thinking of using
some blocking and then a 36 or 48" pipe clamp to apply diagonal
persuasion to get it back in true.
In general screw-type mechanisms are good for providing controllable force
for jobs like this. I've used a screw-operated (not hydraulic) car jack to straighten
things in the past.
I assume you've tried using hand pressure (perhaps with a couple of friends
helping you). These boxes are not as strong as they seem sometimes. They
were designed to be installed in the rack cabinet which provides extra
support.
-tony