The unclued lights (one hyphened and another a novel which is listed in Chambers Crossword Dictionary) display a similar feature — a few of the clued solutions do so too, though to a lesser extent. Elsewhere, ignore an apostrophe.
 

Across

1    Slim, young, lithe person – hot! Just tops! (5)
6    Hosting is problematic as soon as possible (7, two words)
11    Boastful coward showing Cliff a sponge (10)
15    Accumulate stakes (4)
17    Letter about smell of savoury snacks (7)
18    Some shirker twisted marginal reading (3)
19    Dictator books shrubs for TVs (10, two words)
21    Performance by dancing girls receiving round snack (5)
24    Manx house for small islands (4)
27    No sign of telescopic leg (4)
33    Flatfish which has whorls (3)
35    Aussie lorry driver showing restraint about fight (7)
36    Description of fitness regime: chocolate and half a biscuit! (7)
37    Carriage in East End shelter, we hear (4)
38    Scottish prison having to bar the two of them, wearing nothing (9)
39    Weber swaps his tops and dries out brambles (10)
40    Oarsmen wrecked Italian resort (7, two words)
41    Gravel bank in the Skerries (5)
 

Down

1    Single Scottish fellow on refuges in former protectorate (14,
two words)
3    In favour of small display coins (6)
4    Naughty fellow left after twenty embraced German joiner (9)
5    Ways of arousing pity — no love (5)
7    Scots put out by office’s upset (5)
8    Chap on time is Swiss geologist (5)
9    Cobbles from odd two or three Goths. Nothing less (14, two words)
10    100 thebe given to company tie (6)
12    Live on dependants and chat in a friendly way (6)
14    Singing melodiously after drop of ale, port and some soda (6)
20    Musical sign could be left of centre (9, two words)
26    Table for self-catering with unnamed virile chaps (6)
29    Dull work that is embracing alternative technology (6)
31    Where this solution isn’t making one angry (6)
32    Honour completion of paper (5)
34    Lamb schemed regularly in letters (5)
35    Large bulrush cut by one soft flower (5)
 

A first prize of £30 for the first correct solution opened on 29 June. There are two runners-up prizes of £20. (UK solvers can choose to receive the latest edition of the Chambers Dictionary instead of cash— ring the word ‘Dictionary’.) Entries to: Crossword 2215, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.