Called Peter Bowbrick for advice on the bee escapes, and from the confused description I gave him, it sounded as if all is fine.
The piece I was missing was a solid crown board, one with no holes. Apparently it is more usual to put a solid board on top of the topmost super, and put a board with bee escape underneath it - hence you only need one bee escape, with the word TOP on, er, the top.
In my case, because I had no solid top board, I resorted to a board with an upside-down bee escape in it.
OK, next time I'll remember the camera!