I stayed up late last night and had a brief look at this puzzle when it first came online. Could barely see anything, so it was with some trepidation that I started out this morning.
Decided to tackle the theme first and as the potential answers became uncovered, I thought “surely that can’t be a thing?” so a quick detour to google confirmed that yes indeed it is.
After that, I don’t think I’ve ever been quite so assisted by a theme, not that I’m especially into either of the pastimes (although I did once have a small part (ahem) in a work by Spencer Tunick...) but it definitely helped things fall into place. 8d a new word to me, but fairly clued. 3d Young Murphy??!! Inspired! COD 18d though but only after Geeker pointed out that it’s effectively a double themer. Brilliant!