2108: Capital fellows

The unclued lights are of a kind, verifiable in an entry in Brewer. Solvers are required to highlight an eight-letter headword from this entry in the completed grid. Elsewhere, ignore all accents.
 
Across
8 Tax break (4)
12 Clamour of duchy near to collapse (9, three words)
14 Name-board of excellent eatery cut back (5)
15 Hair extract causes commotion (6)
16 12-5 weaving fabric in Scotland (5)
17 First to last, these runners caress (4)
18 Revolting fellow starts belching during dance (5)
19 The delusion of motorway madness (6)
24 Some marrow brought back, left over in Scotland (4)
25 Lake circled by tiny Scottish bird (7)
26 Relation shows no sign of hesitation to stay in Scotland (4)
28 Dutch botanist was acquainted with county (4)
30 Loos shut on back street (7)
31 Loves training in this? (4)
33 Loose bundles in flights (6)
36 Follows Oscar and points to fruit (6)
37 Crazy accepting hospital dips (5)
39 Coward advances, as Goossens retreats (4)
40 Car firm trimmed lace (5)
42 Flower obtained from third cow’s gut (6)
43 Old turban’s needlework insert (5)
44 Went away and completed outside small meeting-place (9)
45 EX-giant (4)
 
Down
1 Slices of thin biscuits for making chips (6)
2 WI tree yielding crab and kale (8)
4 Provide choice of sport and half an Irish team (6, two words)
5 A couple of notes for head of French (4) …
6 … with reports on class arrangement? (7) …
7 … cautioned change of schooling (9)
10 Encroach upon resorts in very French surroundings (8)
13 Flirtation’s not dead — union results (8)
22 He’s not 27 — not 39, I hope (9)
27 Complete score near the peg (8)
29 Awfully mad sort of emperor’s power (7)
32 Money — sort that’s not special, finally (6)
34 Independent king’s up-country (6)
35 Cockney stocking basketry (6)
38 Superior to the B-team privately (5)
41 Half the pasta.