Cryptic crossword No 3,526

Across

1. Serious chap swaps his outer layers (6)
2. Most skilled one gets lucky (6)
3. First Lady’s right all the time! (4)
4. Men with no hope are stirred by new wonder! (10)
5. They provide travel to a French island Sultanate (6)
6. Impediment for ex-scholars having to deal with losing weekend (8)
7. Shed light upon old mathematician running and spilling tea! (9)
8. Milk product has drug inside? For what purpose? (4)
9. 15-faced person starts to drink (4)
10. Small fellow follows mate after second setback for investigator (9)
11. Business district of Newtownards, maybe (8)
12. One gets batty woman to start to knit garment (6)
13. Province distributed coins to go round Virginia first (4,6)
14. Individual savings account? Yes, by Jove! (1,3)
15. Ordering a strong portion of food (6)
16. Seed spread in right area of waterway (3,3)

Down

1. Some cut off nearly everything! (7)
2. Fool returns standard disc inside (5)
3. Responded when traveller was economical with the truth (7)
4. Scan second arguments at end of June (6)
5. Cilia sees Hayle anew (9)
6. Time to move back the old cart (7)
7. Can’t mediate on being wrong to sterilize (13)
8. Settlers: incoming aliens lacking strong leaders (9)
9. Continue 70s music’s captivation of half of London (7)
10. Not informed of French and English articles and goods (7)
11. Desert partly found at a Camargue beauty spot (7)
12. Agree to trick scoundrel (6)
13. Circle parts of last words (5)