I absolutely loved this. Each step of realisation about the complete nature of the theme was immensely enjoyable. And to the point made earlier in the thread about this being perhaps somewhat opaque to Americans, I think I take a slight bit of pride in being one myself (residing on this island) but managing to recognise and appreciate the full nature of the theme.
I had been on a different track for some time, as several answers (some ultimately thematic, some not) share an unrelated topic. Getting the central Down corrected me.
(Spotting the
faux pas was, I think, my favourite moment in my short Listener-solving career to date, and the way it resolved was very impressive.)
Sadly I'm still unclear about a few elements of wordplay, despite a complete grid:
27ac, 34ac, 42ac
Any nudges welcome on those. I have definitions for each.