I got the theme quite quickly, maybe from 34d or 49d, happy to message anyone who wants it, rather than give away a spoiler.
Clues I haven't got yet are:
Across 6, 17, 21, 30, 40, 44, 64
Down 7, 11, 13, 14, 22, 29, 31 35
Happy to supply answers to any of the others..