Cryptic crossword No 66

This is the first crossword I have done that has special instructions. I would welcome comments about which clues you like and which feel are not quite right, as well as any comments about how you found the theme.

Note to self: read the special instructions! I was trying to work out where the definition was in 1d... and only then did I read the instructions! I found this quite tricky, partly because there were a few thematic solutions that I wasn't familiar with, and also because of the additional challenge of knowing which clues the special instructions related to. But I got there in the end, with the help of my crossword dictionary and google. SPOILERS in reply...