The CR signals website (www.crsignals.com) is proving potentially ruinously expensive. They have a much larger range than Berko, including a selection of route indicators. These come in in a range of positions (numbered 1 through 6, corresponding to 11 o'clock, 9 o'clock, 7 o'clock, 1 o'clock, 3 o'clock and 5 o'clock respectively) to indicate which upcoming junction the train is about to take - see Wikipedia or Railsigns.co.uk.
