5/64 & 1/16th ring and max bore size

It doesnt matter how gifted the customer might be in terms of intelligence.. If the customer has reservations it should not be a stretch for a machinist to make a believer out of them. Just dont be afraid to ask. you're not belittling or bashing him. He's not doing this as a favor. He's billing you and you need to know what you're getting (and why) for the money.