14d O, mix variation of the 3rd kind (5) a?i??
16s No beast from the east will cut, these down...unless they're already in your homes! (10) e?e???????
23d Change and never mind the defence to follow (6) no letters
7d/21a A deadline to press is so demanding (2,24) ?n ?n t???
27a They are read-made graves in a war of attrition.
Thanking you
I can't parse evergreens either, although I assume the 'already in your homes ' bit is a reference to real Christmas trees. Do you have any more letters for 16d please