depends how good the annodiser is. you have to put the item in an acid bath until its becomes raw aluminium again - removing particles.How much would it change it?
we've had alot of luxes come in that have been re annoed that we have to size the orings very very carefully - even putting in oversized orings, just to make it seal!I always thought having it re anodised virtually replaced it to the same thickness.
Having said that I wouldn't ever have a marker body ano'd,as I'd be worried about internal tolerances .
I had my Planet backs done and tested the 685 back with a standard 685 black one and couldn't tell any difference afterwards.
Sorry Chris this is your wanted thread!
You may want to request the size backs you are after?