Does he need to get the international license, or is he good to go as-is with his British license? Honestly I figure he'll end up in the same run group as me to start, since y'all don't know him. I'm sure I'll get more than a little ribbing from him over my newbie driving vs his very experienced "nut behind the wheel".
Driver's schools @ Mid-Ohio run by the Buckeye Chapter since at least '86, if not the beginning (1980) have been consistent with having all passing cars pass to the left of the car being passed (passed car stays to the right). Have I not heard about some recent change?
His British license is fine. No need for an international license. I think they are changing that. For instance coming out of the Keyhole it makes more sense for the passing car to pass on the right rather than the slower car to move over to the right to allow the faster car on the left. Whstever they decide, it will be discussed at the driver's meeting.