21a inescapable revolutionary avoiding awkward ban for principal (8). I've now got
e?p?c?a?l - does anyone think it could be "especial"? - and if so, why?
17d (8) I have got "corporal" - is that correct, please - and if so, why?
24a (4) one bird or another with bit missing - I think it's "tern" - don't understand why, though>