Across:
   3. After party (starts after show over finally) (4)
   7. With mothers around, cricket team gets top scores (6)
   8. see 30 down
  10,21dn,19ac,24. Delete invalid characters in '73 piece (4 3 3 3)
  12. Things like 20 2 or 20 16, presented by Keith or Rory (6)
  13. Signs of remembrance sadly mar country ball (8)
  14. Bone breaking painful, naturally! (4)
  15. Wives beaten for opinions (5)
  17. Reputation suffered if many lost (6)
  19. see 10
  21. With no turning around, in a rut, I clue for "a" perhaps? (7)
  22. Pipes one smokes become addictive, as when loaded with strong opiate (7)
  24. see 10
  26. Studio boss dines out with last of pay (6)
  28. Allow entry to weird Mad 12 movie (5)
  29. Surrounded by one in Mad comedy (4)
  31. Injured main polo horse (8)
  32. Hang rogue marine (6)
  33. Police perhaps cycling to civil disturbance (4)
  34. Police member seizes offender's last cable (6)
  35. Block flowing mid-pee? (6)
  36. Movie usually has one quiet group (4)
Down:
   1. Inland U.S. city love a poor actor returning (5)
   2. Tragically stoic Rex, title role of 73 piece (8)
   3. In withdrawal, Russian beast (6)
   4. First rank reel perhaps, absorbing Kyiv's final thrust (7)
   5. 11 with rotating and detailed mission (6)
   6. Purposes of send-off? (4)
   9. Played Rod, hobo in 26's 23 73 piece (5 4)
  11. Years are turned back! (3)
  16. Wreck main characters in burning effigy in 73 piece (6 3)
  18. Band's coyest section? (3)
  19. Band's first section came first! (3)
  20. see 30
  21. see 10 across
  23. One with partner, penetrating and lively (8)
  25. Wrong time to abandon God perhaps? (Such tales told in 27 French 73 piece) (7)
  27. Steamy and strangely lusty, securing restricted movie rating? (6)
  28. Skillful 33 going off after promotion (6)
  29. Member of Adam's band, in misanthropic section? (3)
  30,20,8ac. North generated bizarre fantasy of the East in '73 piece (5 3 6)
  31. Show model behaviour when old fable writer turns up, losing his head (4)