Whenever I've needed to remove a bonnet to replace an engine, I've always marked the position of the hinges carefully before removal. It saves a lot of heartache later.
Refitting body panels is a black art; most large car dealers have one, usually ancient, fitter who understands the magic.
I once took delivery of a new high end German car and was sure the drivers door wasn't sitting quite right . The selling dealer told me to bring it in on Tuesday, 'cos it was a job for Bert, and that's when he'd be working at this branch. Tuesday arrived, Bert was duly summoned, and this wizened old gentleman with faded overalls and a rollup dangling from the corner of his mouth drove it into a hut at the back of the site and shut the door. The complimentary coffee machine had barely done its stuff when Bert reappeared, job done - and it was perfect .
I asked him what he did.
"You wouldn't want to know" was his reply. .
I’ve been told many times, you wouldn’t want to know, especially with bonnets. Lots of yanking and bending I believe.