Express Cryptic

[iggymiggy]

14d he wrote poems in french about airplane oil(11) a?o???n???e
15d worried about oil, aim to get collectibles(11) a?t???b???a
21a lime curd spread on instrument(8) d??????r
28a mollusc shows change in value(8) u??????e

[emeritus]

14d Apollinaire

[emeritus]

http://en.wikipedia.org/wiki/Guillaume_Apollinaire

Anagram

[Lie-in King]

14d Apollinaire - anag 'airplane oil'
15d Automobilia - anag 'about oil aim'
21a Dulcimer - anag 'lime curd'
28qa Univalve - anag 'in value + v(olume)' (clue reads "...value, including volume")

[emeritus]

15d Automobilia (Anagram)

[mazie]

15d Automobilia

[iggymiggy]

thanks to all