Himself writes: I have been making some of the plethora of signs and signals that have sprung up at Beddgelert. It's quite a task because none of them are anything like standard gauge railway signals so there's nothing available commercially which can be adapted.
(The 20 pence piece is there just to give you a sense of the size of the signs)
We have been fortunate to have been given the signalling schematic drawings which enabled me to scan each sign individually and reduce them to 4mm. I then laser printed them onto photo paper, which then has to be sprayed with 'Crystal Clear' to protect the print, and then they are bonded onto 20 thou plasticard, which is in turn glued onto the posts and painted.
The most difficult ones are going to be the 'ladybird' signals which are illuminated by two amber lights positioned where the top and bottom black spots would be.
This will require some experimenting to find the best way to make them work - either fibre optics, grain of rice bulbs or LEDs - the maximum size for the light hole is 1.8 mm. I suspect the fibre optics strands will like the sharp 90° bend down the post so that option may not be a goer.
The other signal to make is the point indicator light which is in the style of a single lamp traffic light.