Cryptic crossword No 1,626

Across

1. Averse to truer presentation of what's most dear (8,5)
2. Call to plug American conference (6)
3. Huey's uncle old and broke (6)
4. Flat in key a first essential to exciting venture (8)
5. Sign on stuffy little schools (9)
6. See 1
7. Nitrate blend or Semtex? Keep back! (7)
8. Hill scheme in urban dictionary (6)
9. Roast beef with all the trimmings maybe keeps temperature for early service (6)
10. Baddies have right connections? (7)
11. Make sign of deference as Armstrong hailed for joint first landing (5)
12. Makes little of blue scenes (9)
13. Most extreme two ways to contain back-stabber  (8)
14. Base in Rome hosts gathering - the opposite, in truth (6)
15. 5 in when things said? (6)
16. Jumpers, say, set out on the slate (8)

Down

1. Criminal dumping Calvin Klein jumper (3)
2. Company quitting fuel section is big concern (5)
3. Girl rounds off foreign articles on America in neglecting employment (10)
4. Pep's best once in Barcelona? (6)
5. Peter's crew after disclaimers (4)
6. Peru space round capital (5,4)
7. Unanimously separate in all parts of Lundy (11)
8. On lacking 19 take in advances as before (11)
9. Aidan's singers (5,5)
10. Concession the men demand in restoration (2,3,4)
11. Venetian lady finds airport without right turn (6)
12. Go for a 5 in general (5)
13. Bits cut out for budgerigars? (4)
14. Caustic tale narrated (3)