the first 500c comet and meteors were at the Earls Court show nov 1948 both were built in cycle assemby they had series B rear frame with the brake cable bose machined off and a make shift series A rear brake lever picture in Roy Harpers book the vincent gallery page 55 I do not think they were sold like this because after the show the series C rear frame came out. the oldest Comet I have seen in Australia is 2A 2839 mating number 75 frame number RC/1/4739 George Browns first race Comet was 2921 made by his brother Cliff