Seven unclued lights (one hyphened) are 23: 7A + 17 + 40 + 5 + 6 + 31 = 36. Ignore one accent. Elsewhere, ignore an apostrophe and two accents.
 

Across

 
1    Half per cent off haircut (11, two words)
11    Girl crafty in conversation (6)
13    Lunatic ran through crazy Swiss town (7)
15    Stop charging about part of church (5)
16    Scots ask gentleman about Peru (5)
18    Friendly earl cuddled priest’s daughter (5)
20    Yarn one from Paisley spins in recurring patterns (6)
21    Sack or Martini? (5)
22    Electronic system tap-dancer contrived ejects CD (7)
27    Ship’s position, say, eagle flying takes on board (7, two words)
29   ...