Note: The clues are a mix of printer's devilry and normal cryptic clues.
Across
1. Pillars bend within seconds (6)
6. Essentially elevate temperature in volcanic matter, forming a river (6)
11. Pillars protecting representative group of soldiers (4)
13. Egg-shaped, large fruit in Australia sent back (4)
14. Respected leader in South Asian country (6)
15. African teacher's assistant captures large bird (6)
16. Female's help accepted by males (6)
17. Redding, Iowa: Strikers disappear seconds before supervisor's entrance (4)
18/37d. Strikes from six o'clock on are taken evenly on a disc (4-4)
20. Auditor's tomb showing abnormal growth (4)
21/19d. Loiterers playing all-star team, at last taking first place (4,4)
24. Man with goal to become batter (4)
25. Lord Stanley's end? Too soon (5)
26. Endlessly angsty about small nuisances (5)
27. Electrical discharges destroyed cars (4)
28. He cut his side band his beard (4)
29. They were promised free quality and justice (4)
30. Selling of cruise for the audience (4)
32. Singer's sorrowful face, in the end (4)
33. The road was blocked by falls (6)
38. Both sides cut from Portuguese region's plants (6)
39. Mr. Gingrich working as a scientist (6)
40. Arm aid wrote a parking ticket (4)
41. Items placed on a fur face (4)
42. I give out stuff, primarily for principles (6)
43. Hire Dion musicians? They eventually formed their own band (6)
Down
1/34. Session mostly held to depict delicacy (8)
2. Fish doctor banished from chilly region (4)
3. Race started at Napoli's speedway (5)
4. Young man has me put down (4)
5. Exhaust is an important part in a car (4)
7. Register containing unknown composer (5)
8. Articles about five sailors' appearances (7)
9. Basic vehicle I will acquire at first (7)
10. Chicago mob boss seen with a Sicilian leader, unfortunately (4)
12. What Jupiter has for a long time (4,5)
15. Will's misleading statement (9)
18. Part of Italian course ends in disaster – media blaming university (4)
19. (See 21 across)
21. Twisted fraud to get computers? (4)
22. Instrument of one spreading falsehoods on the radio (4)
23. Furiously angered (7)
24. Guy meeting delegation (7)
29. Glen drinking whiskey live (5)
31. Shaw, the jazz musician? That's art at the very top (5)
32. I am a Southern – take that back – a Northern European (4)
34. (See 1 down)
35. It's in the past, in the past, endlessly… Unbelievable waste (4)
36. Trapped between neon signs for ages (4)
37. (See 18 across)
