Across:
   7. County keen to eliminate a couple of characters (4)
   8. Small gallery in the country (5)
   9. Left ship for a bit of fun (4)
  10. Grasp hero identity hosting Union Ball perhaps (8)
  11. Nine held by non-US leader who chose to invade 25 (5)
  12. It could put a whole in one beastly male alien (6)
  14. One resting poorly could be in the worst mood (8)
  16. Manic dentists with less time for disagreement (7)
  17. Standard issue 8 across 13 where May 1970 saw 8 down (7)
  20. 8 across breaks an outbreak (8)
  22. Study excluding the elements for creative writer (6)
  23. Something of a colossal volley? (5)
  25. California mob crazily return assistance to foreign country (8)
  27. With moving short message, left school (4)
  28. Cutting nibs encouraged creative writer (5)
  29. see 3 down
Down:
   1. Army wheels, full of energy, jump without hesitation (4)
   2. See pelts tanned for High Church decorations (8)
   3,29ac. Radicals being bashed by New York unionists, as such patriots regularly hear reds' hearts ruin oath (4 3 4)
   4. Head of 13 adapted and included head of 27 (4)
   5. Young Romanov was greatest around former Empire's leader (6)
   6. When embracing true work, nosed with grin? (10)
   8. His son got hurt in unfortunate affair at 7 8 across 13 (9)
  13. Union's left wing remain in extremely academic place (10)
  15. Like a bad dream, guns which were turned on civilians at 7 8 across (9)
  18. New day broke for a new type of warrior? (8)
  19. Scientific leaders restrained by secure authoritarian (7)
  21. Determination of runner perhaps overtaking most of the column (6)
  24. Short greeting between rounds of 7 8 across (4)
  26. One trick often used on computer (4)