Ontario RV-7A builder Mike Shields has flown his aircraft across the Atlantic. He flew from Ontario to Halifax, NS on July 3rd, to Iceland with a stop in Goose Bay, Labrador on the 4th, and to Scotland on the 5th. You can get info at:

He has Jon Johanson's tip tanks, plus a 32 USG flexible fuel cell on the pax seat, for 93 USG total fuel.