Spectator 2202

[Matakari]

Thanks for some help for the following:( Wherever possible, a rationale would be appreciated.This is for my own pleasure as I get to understand the subtleties of the Spectator...One of these days, I'll be ready to submit the puzzle!)

16a - Scots ask gentleman about Peru (5) : ??E??
21a - Sack or Martini? ( 5 ) : ???L?
27a - Ship's position, say, eagle flying takes on board ( 7, two words ):L??????
41a - Seven sages tango, livening 20 January ( 11, 3 words):????N??????

1d - Myth involving litre stirred like coffee?(10): F?????????
2d- Tree Q climbs aptly arrayed(8): E???????
4d - Sybil's quality aroused poetic shrimp(12): P???????????

[dannyk13]

21a.Rifle -to sack also Martini is a make of rifle

[dannyk13]

1d.Filterable -anagram of litre in fable(Myth)

[shaneystar2]

s(pe)ir (pe .peru and sir,gent)
rifle (double def)
lee gage (eagle eg)
st agnes's eve (anag)
filterable (litre + fable)
Eucalypt Cue(q) and aptly
Propheticism (anag)

[Neveracrossword]

27 Lee Gage, a ship's position. It's an anagram of 'eagle' and eg'/say.

[Captain2]

4d propheticism (anagram of 'poetic shrimp' + Sybil was a prophetess)

[Matakari]

Many thanks to all! I am getting closer to understanding the anagrams!