There is quite a bit of information for dating Campagnolo hubs in the Campagnolo Timeline at: http://www.velo-retro.com
As far as replating three-piece (FB style) Campagnolo hubs:
You cannot replate the steel center barrel with the alloy flanges still attached. You use an automotive gear puller to remove the aluminum alloy flanges from the steel center barrel. Heating just the flanges with a propane torch before removing helps a lot. The aluminum flange expands _much_ more rapidly than the steel barrel.
The portions of the center barrel that the flanges are pressed on must be masked off before chrome removal. In other words, you are just removing and rechroming the part of the barrel you see, not the interference fit area of the barrel that the flange is pressed on. This area is centerless ground to a press fit and it is important to preseve this dimension!
When reassembling, you should again heat the flanges and use a automotive bearing press if possible. I would also recommend the use of red Loctite (bearing mount). Be aware that the holes in each flange need to be staggered in relation to each other; very important but easy to overlook.
Historically the rear three-piece hub had a problem with the drive-side flange coming loose. The forged one piece aluminum Record hub that replaced the three-piece steel and aluminum alloy Gran Sport hub solved this problem along with the more obvious advantage of being lighter.
Chuck Schmidt
South Pasadena, Southern California