2093: Leading lights

The unclued lights (all verified in Brewer 18th and 19th editions) are of a kind. Elsewhere, ignore three accents.
 
Across

1 Overcome old film broadcast (8)
6 Tawdry item – small company holds a pile (6)
12 Ivy, out east, is after fish which have four faces (10)
13 Farewells losing one of two (5, two words)
15 Kite for flying over archaeological work housing a bit of loot in wood (10)
16 Years in France by border of city (7)
20 Leaving old flame with sex appeal (4)
22 Make a coat? No ideas circulating (7)
23 Official diploma that’s guaranteed (4)
24 A loveless pair with helpers – dozens! (7)
30 Hillside cutting up near Balmoral (4)
34 Garment from Bantu people losing heart (4)
38 Leaving quickly, Jack’s giving support without note (10)
40 Olympic Lord accepting first two of the honours for swimmer (5)
41 Loud Welsh girl circling shelter with non-commissioned soldiers (10)
42 Tailless dog for Blott’s creator (6)
43 Songs for one playing dominoes (8)
 
Down

2 Submarine earned US worry (8)
3 Pièce de musique que tu détestes un peu (5)
4 Greek runner lost bit of apple in the US (7)
5 Art isn’t representing a white van, say (7)
7 Journalist lost his life – in a whirlpool? (6)
8 Lively artistic director at the Old Vic loses his head (5)
9 Rove cryptically? Too much? (13, hyphened)
10 Duchy with US bank-notes – greens? (13, two words)
17 Seagull’s gullet (3)
18 Call, taking route from prison (5)
19 In France yesterday, crash involved chief priests (9)
21 Little house under a mountain that’s called Gem (5)
27 European joiner at either end of the Tube? (3)
28 Part-time sportsman breaking promise (7, hyphened)
29 Deputy on his feet in Walford (7, hyphened)
32 A pound of seed (6)
33 Dined at pub – that’s only natural (6)
35 A party will disconcert (5)
 
A first prize of £30 for the first correct solution opened on...