ACROSS

 1  Not the campfires watched, by Rebel pickets. (8,6)

 9  Monkeys decorations, by the sound of it. (7)

10  Dress for the audience. (4-3)

11  and 5 down Probably lighter than “I was a Fugitive From a Chain Gang.” (6,10)

12  A chap commonly can stand a drink all around, with enough silver. (5)

14  Perhaps not legs with the furthest reach! (7)

15  Type secured in a chase for printing or for manuscript. (5)

17  See 13 down

19  Marks the sailor secures. (7)

21  Fail to exclude the apostle? (5,3)

23  and 18 down How things appear when you’re down? (3,3,2,2,3)

25  Staying gloomy, no doubt. (7)

26  A few songs on the side? (One hopes the take-off is successful.) (7)

27  25, perhaps, completely gone! (3,2,4,5)

DOWN

1  Taking the census in Meninburg? (9)

 2  Not a very conventional root. (7)

 3  Two to make the d of England. (4-5)

 4  Got up like 6 when it loses its head, in a way. (4)

 5  See 11 across

 6  Furze. (5)

 7  Pig’s foot, sometimes in harness. (7)

 8  and 20 Most, as a type of accelerator. (4-7)

13  and 17 across Cow, perhaps, but certainly not a purple one. (4,3,3,5)

15  Foul play might lead to it in court. (4,5)

16  Cut off in the middle, pared on the outside, and completely edged. (9)

18  See 23 across

20  See 8

21  Poetically 4, for example. (4)

22  Is this well-known factor in zero? (Or is the animal associated with cash on the nose?) (5)

24  This artist doesn’t have his face lifted exactly–just made up differently! (4)