Plating Hyd. Valve Spools w/ Hard Chrome

[Daveleeander]

I want to recondition some old Hyd. Valves on a tractor of mine. I want to ream out the valve body until the surfaces all clean up, and then instead of turning new spools to size, I would like to plate them until they reach the proper size. Before I go to the expense of buying a kit, learning to use it, etc. I thought I would ask about the feasibility of doing this.

Question: (1) Can I polish the old spools (chromed if it isn't worn off) and add more chrome to existing, or do I need to grind off (in lathe) any old finish first.
(2) How accurate can I expect to be (with some practice) as far as thickness of layers with time (I have the on line manual and have read the hard chrome portion).

Dave