23a Help religious ceremony (7) --R-I-E
14d Spoil an addition by a student using marble (9) M-R-O-E-L
15d Neat, small, fashionable form (9) S-I---A-E...
23a Contract hardly on seat (2-5) N-, --U-P
28a Frenchman joins kind fellow deliverer (7) M---M-N
24d Time and determination to get material (5) --I--...
4a Dart at large tree, getting injury (8) ---P-A--
5d Worker picks up tab, ordering ornament (7) --T-A-D
8d Diana, say - her with the nut recipe (6) --N-E-...