Across
1. Arrangement to see about cut for B5 (7)
5. see 32
11. Some spinning spinning drink (3)
12. Windows, say, in backing of T5 (2)
14. see 57 down
15. Obliterated early leader in slam-dunk (5)
16ac,43ac. Prog band ply kind of novelty (4 5)
17. Note: extension given by this (3)
19. Light metal in backing of T6 (2)
20ac,6dn,63ac. "Star Spangled Banner" is about vitamin B2 (2 3 4)
22. Loud one for T4 (2)
23. Badly dyed as swirl (4)
25. see 39
27. Brief education of Sullivan? (2)
29. see 46
31. Second round for T5 (2)
32ac,5ac. Support in "Mother" with 49 down for B4 (5 6)
34. see 56
36. On/off rejection? (2)
38. Urban West Coast sound for T6 (2)
39ac,49ac,25ac. Make pesto sauce A1 (5 2 2)
40. The Spanish American railway? (2)
41. French... and alien! (2)
42. Chinese Greek character (3)
43. see 16
45. Computers etc. in backing of T7 (2)
46ac,24dn,39dn,18dn,46ac,60ac. A plus B put together by 16 43: problem with exposed rear? (3 4 4 2 3 4)
46ac,30dn,29ac,51dn,46ac,10dn. True heroin ("one taken by heron") gets soldiers, along with cooler number "n" for A5 (3 5 3 2 3 3)
48. Some weight in album! (2)
49. see 39
50. Links on site crashed (4)
52. Record easy bits for T2 (2)
54. Poem among seconds of Kipling offerings (2)
56ac,46ac,34ac. Unthrone unhinged A3 (2 3 3)
58. How old? About, say, one? (3)
60. see 46
62. Suddenly pulls last of heavily armoured vehicles, losing 49 down (5)
63. see 20
64. Hesitation in backing of T2 (2)
65. A party kerfuffle (3)
67. see 57 down
68. Ate herb cooked for A2 (7)