Across:
   1. 18 24 call it a small portion (5)
   4. 18 24 12 pennies? Take another! (9)
   9. Texas burg lass with singlet on (9)
  10. Corrosive fluid damaged pipes (5)
  11. 18 24 and hollow 22 18 24 (6)
  12. Initial expenditure cap could be so (8)
  14. 18 folk sowed first parsley and thyme without starter (5)
  16. Rouseabout dropped small Australian beast (4)
  17. Former 18 leader in creative arts (4)
  19. see 18dn
  20. 18 24 240 pennies to Irish republicans (4)
  21. Took back pound paid when first two pieces never provided (5)
  24. see 18dn
  25. 18 24 reflecting fine run - first class (6)
  28. In abacus, a general application  (5)
  29. Alongside that, he threw it out (9)
  30. Taking care of bush transportation with railway (9)
  31. Warrior in action in jailbreak (5)
Down:
   1. Diet features sources of fibre, otherwise glues me! (7)
   2. 18 24 raised Queen a heap (5)
   3. Most aerodynamic kites cut through the nasty weather, ignoring it (8)
   4. "Tess" shot here? (4)
   5. Playing horn, a naive one of the early Georges? (10)
   6. Stares unpleasantly, taking in quiet outcasts (6)
   7. Given relief, such as coins? (9)
   8. 18 24 manual, using both hands (7)
  13. Crook decides... act desperate for a drink (10)
  15. Ways to transport forces? (9)
  18,24ac,19ac. 16's forerunner, strangely run pecuniary e-counter (8 8 4)
  19. Crude organisation with savage touch (7)
  22. 18 24 excitement about check (7)
  23. 18 24 Europe set about providing (6)
  26. British are leaving one place of study operating (5)
  27. Tax very harshly changing hands (4)