Spectator 2176

[Matakari]

Good morning! Got off to a good start with this one, but stuck on a few. Some help is appreciated with the following, please:
ACROSS:
29 Not acquired - left in or left out ( 8 ): ?N???N??

DOWN:
5 Boards to send by river ( 10 ): ???M??????
15 Mexican dish - half sauce and beer ( 6 ): ????G?
19 Relative ain't changing in country ( 10, hyphened ): ???N?N????

Thanks in advance!

[Neveracrossword]

29. Unearned (if there was an 'l' for left in it, it would be 'unlearned' - so not acquired in that sense too).

5. Committees, boards (Commit, send+Tees, rivers)
15 D. Your 'g' is wrong.
19 D. Great-Niece (anagram of 'aint' and 'Greece', country).

[Matakari]

Thanks, Neveracrossword!

[whatsthat]

19 D is even easier - an anagram of aint in GREECE