Glad it's working now, but when, not if it starts to leak again, you need to find yourself a real machinist. Look for somebody with a "Blockmaster" milling machine and an operator who knows how to use it. I would usually take .010" passes off a head or a manifold, and the entire job should take about one hour or less, after a relatively simple setup procedure. I could see a concern with heat buildup if a belt sander type head surfacer was being used, but a mill is a different can of worms.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!