If a distribution(Match) is processed for a participant prior to a plan restating to EGTRRA, should the old vesting schedule be used or should the 6yr graded be used.

You can't operate the plan outside of certain EGTRRA changes regardless if amended or not. The required minimum vesting schedule for matching contributions applies to matches made for the plan year beginning in 2002. If that participant received some match dollars for that year, those dollars need to have the minimum vesting applied, while the other match dollars can have the old schedule apply. However, most people that I have heard of are applying the new minimum match vesting to all match dollars to avoid the recordkeeping hassle.