Having just managed to parse all clues, I think the comment from drxx @4 is spot on. For me, there are two problems wrt the fairness of the clues. Firstly, some of the definitions used stretch the limits. That in 33d has already been well commented on, but the clue for 22d should have "that" inserted to match the definition used in chambers and 35a & 42a are dodgy IMO. Secondly, it would have been impossible for me to finish this without the internet. I could not parse 15a nor 2d, nor understand the answer to 15a, without resorting to Google and wiki, and even then the descriptors used in both are, IMO, very obscure and would never of surfaced without help. Still, generally a very good crossword with a very neat end game.