Mephisto 2617

[foxspur]

12ac Flick through worn folio with reddish binding (10) GOLDFINGER? I can see ginger and part of folio, where's the D come from?
27ac It help keeps on track of girl, maybe, with deceiver about (9 two words) I have ?UI?E RAIL
29 ac Old horse almost retired, retains part of headgear (7) EARFLAP?
24dn Composer, sapped of energy, crosses a mudflow (5) LEHAR? Why?
All help appreciated

[bibblebub]

12a worn folio = old f

[bibblebub]

27a guide rail

[Captain2]

27A Guide Rail

[bibblebub]

29a horse = PALFREY, almost retired = PALFRE(y) backwards = ERFLAP, i assume there's also an A in the clue ("...retains A part..." maybe?)

[baitress]

ginger with old + f(folio). old being worn.
27a guide rail.
29a - looks like palfre(y) with a in <

[bibblebub]

24d LAHAR is a mudflow - L(e)HAR with A in the middle

[foxspur]

bibblebub, Captain2 and baitress, thank you very much - brilliant!