I'm slightly puzzled by 23 Across
Swimmer that strong needs to produce air (5)
t-o-t
I see 'trout' but not sure why, apart from it being a swimmer. Any thoughts?
Last one - so any help would be greatfully received.
52 Across What Dante wrote of differed from Perec's novel (5) s-d-s
(I'm not 100% sure of the first 's')