Cryptic crossword No 3,631

Across

1. Wattle and daub screen made economically with factory seconds (6)
2. Grave concern about England being a long way off (4)
3. Can enlist, taking information for hospital (4)
4. Mixture of myth, 2 and raving nonsense... group who united chasing noble 32 (10)
5. Jacob's son is benign, although not good at accepting a difficult situation (8)
6. Great English leaders or, say, revolutionary? (6)
7. Major, one that smoulders when he's in congress (6)
8. Sued for misrepresentation? That's not new! (4)
9. Lead actors take time for launches (6)
10. Panama perhaps welcoming king in the flesh (6)
11. Tasmanian river saved by activists with forthright position mostly (8)
12. For capital, nothing was changed (10)
13. House always shows America's great one having "Eye of Providence" (4)
14. Say, finale of "Nine to Five" returns (4)
15. Ancient fellow doubting new maths with "zero" included (6)
16. Remove 32, which is stipulated in fine print (6)
17. What film says Beckham does to it (without using his head) gets goals! (4)
18. For taxation, second parts of deal expected... accordingly, give us representation! (6)

Down

1. Belief rocked with changes after king departed (5)
2. ABC reworked popular part of 4 21's origin story (5)
3. A patriarch, a supporter, and something his people won't swallow! (7)
4. Socialist heart of 2 (3)
5. Perhaps 9 25, 13 28, 17 across 22, 30 8 discovered in groups around first leader (8,7)
6. Wobbling legs, with sea going on and on (7)
7. Beck and son embrace Queen, band with airplane and then starship? (9)
8. Study of each going into Richmond after evacuation (4)
9. Layer of history effaced near sources (3)
10. American high ground providing Australia briefly with sanctuary (5)
11. Primarily by American Checkers, king would alone roam direction stated? (9)
12. Foolishly, 13 accepts a prophet (5)
13. Local inn touring, not with a car (7)
14. In first bet, trap for girl (7)
15. Bogus claim at heart of 2s (3)
16. Main thing first which a politician seeks? (4)
17. Keeping stiff upper lip despite not getting turn in rampant coitus (5)
18. A mother's type of apple? (5)
19. Struggle, with five against one by the end (3)