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 –...