Across:
   7. Where art's nature is "cooked" (10)
   9. One piece of a family tuna casserole... (4)
  10. ...proved cheaper than crude nut paste (8)
  11. Stay left, avoiding first branch (6)
  12. Older students injured in maul (6)
  14. Sex party? (8)
  15. Police acid's OK ... quite trippy with nice visual effects (13)
  18. Wave the flag for some breakfast in Canada (8)
  20. After revolution, see Che for food (6)
  22. Her sin compromised memorial (6)
  23. Name mysterious tin deity (8)
  25. see 1dn
  26. Boring is rough on ends of bit (if you drill) (10)
Down:
   1,25ac. Strangely pale bone in taller specimen (4-4)
   2. Cryptic master to provide content on internet (6)
   3. I cut chintz into pieces, having no time for the green (8)
   4. One lot sold, some got sent back or taken away for free (6)
   5. Raid porn criminal, a tiny contributor to the deluge (8)
   6. Movement having seen strict cuts (10)
   8. Widdershins mixing wine cocktails (13)
  13. Odds and evens written in old ink we'll wish to hold (10)
  16. Spied old building, askew (8)
  17. Spied following bird, askew (8)
  19. A site for a road (6)
  21. Modified a street, not right for property (6)
  24. Shut out hence (4)