If it has been many years as you suggest... I would:
1- open up all the wheel cylinders and strip them down to nothing... remove everything
2- if they don't have any corrosion in the cylinder chamber then blast all the crap off of them and paint them black if you like. (don't get any paint where the brake fluid will live)
(if they are corroded... even a little... then throw them in the trash buy new ones)
3-if they are not corroded then hone them with a special little honing tool you put on your electric drill.
4- install rebuild kit bits and put them back together
5-Clean up the adjusting stars with a wire wheel... grease them with some white grease before re-installing.
6-Replace ALL flexible lines
7- If there is ANY rust in any of the hard lines I would replace them too. I have had "blowouts" of hard lines twice (usually in the long line that goes front to rear)
8- buy the little rubber caps that go on the bleeding valve tips... to keep out crud and water... manually bend the little keepers that hold the stars back where they are supposed to be... so that they actually hold the stars rather than let them spin.
Read the manual on bleeding brakes.... you'll need a friend to help.
1234 applies to master too...
The little hone tool is usually available at most auto parts places.
protect me from what I want