They didn't have a real final in the 1950 World Cup, the tournament ended with a final group of four teams playing each other once. Still you could say that the match Uruguay - Brazil, which George Rerader took charge of in the newly built Maracana stadium, was the final.
At 53 Reader was actually retired in 1950, but FIFA recalled him for the World Cup finals.
Reader started as a player an became a ref in 1930. His international career never really came off because of the war, so he was very lucky to get another chance. Already retired from national football, he was first recalled by the FA, later by FIFA. For international matches and finally for the World Cup.