The unclued lights are of a kind, verifiable in Brewer.
 

Across

11    Oil-well cap adjusted as ornamentation (10, two words)
13    Some entertainer, dynamic, but socially inept (5)
14    Horseman’s additional clause (5)
15    Half-scores I have in short are nerve-racking (7)
18    Wicket that is most unplayable for a batsman? (6)
19    Jack’s heard something in church (4)
22    Len rummaged in the locker with gusto (6)
24    O, Gorblimi — it’s a mess — it’s a tangle (9)
25    Cross beams? (5, hyphened)
26    Cycling clubs arrived in holy city (5)
28    Sirocco winds in the middle of summer — small world! (9)
30    Grievance of pastor with post-Reformation Latin (6)
33   ...