fits very well the theme

you would have met any color challenge ...

Don’t really understand what are they for but both your photos are +++++++++

What are these? I can't figure it out even in the global view.

Found this... en.wikipedia.org/wiki/Lever_frame

most beautiful

Have not heard of Bo'ness, but looks a great museum to visit. So these were presumably used on the railway, physically located in the signal box? Found this... en.wikipedia.org/wiki/Lever_frame

A superb find that fits the challenge perfectly! Those were the times when many things were done manually...

It must have been a very skilled job. Nowadays there are very few trains running because of strikes. ;-)

We've also had strikes this year, I had to reschedule travel plans... And by autumn the train drivers union probably will start striking:-(

Difficile de mieux respecter le challenge, avec, en reserve, de nombreuses couleurs pour des futurs challenges de même catégorie. Il semble que quelques soient les pays, les grèves dans les transports sont devenus "sport national"-