Cryptic crossword No 3,946

Across

1. Forward a record about national leader (5)
2. Boast new fancy headwear (5)
3. Runs off with eastern medicine man (5)
4. Force in China? (3)
5. See 28ac
6. Track on waterway's periphery accommodating tugging horses primarily? (7)
7. Belt at heart of fears (3)
8. Dirty article presented by relative (7)
9. Typical ironic lass I cast in part (7)
10. Permitted actions in system for data access (3)
11. Mob's rough play involving a lot of violence (5)
12. Leak fake extract about author who wanted his unfinished work destroyed (5)
13. Competitor in 30 31 perhaps beginning to talk with Harold about eye pierced (5,7)
14. Wrote about fish rendering process (9)
15. Always losing first couple in hustle, wagers uptakes being close to 4 across 21 and last part of 7 1 across 11 (2,5,6)
16. See 30ac
17. Set of 28 collecting rent let loose (6)
18. 126720 in wet Milo disaster (3,4)
19. Unscripted pre-meet arrangement involving a hug and a kiss (9)

Down

1. Sweet but thick, Tracy takes ecstasy AND a bit of LSD (7)
2. Start of main trouble? (5)
3. Spin hit single, his first (7)
4. Ghost, last to possess 16 perhaps (4)
5. Chinese instrument shown off by 7? 7?! (5)
6. Fix wasteland (4)
7. Loud piece of music in movie (5)
8. Quote Wade's opponent in 1973 with both sides of the coin, not being concerned with the practical (9)
9. What I do at lectern, or what I did at table? (5)
10. Ironic lads I cast out as they proved hard to penetrate (9)
11. Casually canters away, leaving leaders of family that came before (9)
12. Party casually canters home for 30 31 (9)
13. Made from ground ash, wicket is most bizarre (9)
14. Reports sadly past due (7)
15. King replacing knight changes attacks (7)
16. Fish is large and strangely lonesome (5,4)