Tough going this week, but am almost there.
39 A. Chemist put concoction in front of Major (6) l?e?i?
51 D. Woman that's opening immoral houses? (4) ?a?d
I can see 'maid', which has 'i'(opening 'immoral')but don't see where 'houses' fits in.
35 A. Is Queen wearing my granny's sou'wester? (10) ?o?n?s?m?n
The only word I can think of is Cornishman - but I can't see how it fits with the clue (I've got a little thought that the Cornishman train went from south to west, but don't know where Queen and granny come in).