Hi. Have been trying to remember the make of my mates 5 speed racer from the seventies. I haven't got much to go on other than it had a simplex derailleur and it was metallic brown. Falcon seems to have stuck in my mind but could have Claude Butler or Dawes. Contrary to the talk nowadays we thought his simplex derailleur was better than the Huret on my Raleigh as it was always mine that ended up jammed in the rear wheel.