Thanks. Their nav lights are all too big, unfortunately. That seems to be the norm. I think I will have to go fibre optics. I'm told I should construct a box with a light source, and run all the fibres from that, with coloured filters as necessary. I'm researching how to do that. Good news is that tubes for masts will still be in scale.
Thanks for replies so far. If anyone has a contribution about using fibre optics, that would be great.
The sign on my cabin door said 'Not enough bucks stop here'.