falcon4, The ball va. manu'f. I know manu'f. their own balls. Undoubtedly, there is a reason why you don't. Have you checked the Thomas Register looking for machine shops that can do this type of work. You're going to find that most Valve Manu'f. will only be interested in their own production operations and requirements. Also, there is the issue of helping out a competitor.
Another thing to look at is, have you inadvertantly set your tolerances and specifications so high and tight that acheiving it is next to impossible? Just some food for thought.
Check for machine shops in the Thomas Register.
saxon