Cryptic crossword No 3,167

Thanks, the first of yours I've done, I think. Especially liked 1a,27a, 1d,8d

Asking for feedback: do the surfaces make more sense now? How about the difficulty? Is the crossword too hard/easy? (@PostMark, @coot (because I know both has visited my previous grid and this grid), anyone?)

Enjoyed this one! 27a is a great clue

Thanks SGITF for an enjoyable and approachable puzzle. Once again, the succinctness and accuracy of your cluing is impressive. My favourites were: 1a, 23a, 16d, 20d and 22d. Spoilers …

Really fun!