[dirtyjim]

I would definitely flush every couple years at the minimum and replace the brake lines if they show any signs of rust.
last time I bought calipers they were $17.00 each with a $10 core. I rebuilt a set years ago but now I think i'd just buy new unless I planned on powder coating or something.
I know I've been guilty of spending hours rebuilding something that can be replaced for a couple bucks more times than I can count