Peterm, your comments inspired me to have another look at this. Am (quite) enjoying it, but think I might have gone wrong.
15 D. Serve e.g. bumpkins devouring what's mostly underdone (8,2 words) ee??????
10 D. Cheap labourer, an outstanding one cutting big trees in pieces (12)
s?st?r??????
It'd be good to know if I've made a mistake somewhere.