Gloobey: Nice one!
The base plate doesn't really click in. But it fits perfectly and stays in place. Like it was designed for this! It is hard to explain for me since English isn't my native tongue.
Another question for you: Those train signals in your picture, are they purely decorative or are they connected in a way to the switch
Little Jo: Nice tip, I hope they are still available from DS.
Rasputin: It is not railings I am concerned about (but great tip I didn't know that part existed). It is the fact that the klickies actually have to jump from the door to the ladder!