Cryptic crossword No 1,576

Across

1. London transport bribes oiks to get knotted (5,5)
2. Some baby teeth bit? Eight of them (4)
3. Clinician with medical procedure cancelled delivery (4-3)
4. Attacks promotions for Japanese pillboxes? (7)
5. Nonconformist tramp cycling (4)
6. Old London transport unexpectedly snubbed? Yes (5,5)
7. Clobbers earl with a spanner on the way north to Chelsea (9,6)
8. Totalitarian leader emerging from giant cathouse, say, turning right at the end (3,7)
9. Zip caught in knot of hair’s a silly mistake (4)
10. Solid fuel booster’s first stage on rocket at first quite volatile (7)
11. What’s sold at a German spa auction by a disreputable fellow? (1,3,3)
12. Help a bishop estimate temperature (4)
13. Dune’s transport from a tree reportedly full of insects (5,5)

Down

1. One attempt to buy in the same place (4)
2. Clasp spectacles entering British church (6)
3. A drunkard outside heading to cup tie (5)
4. Bravo! Use oil & start to fathom out alternative power sources (8)
5. Bow down to take greeting in the rear (6)
6. Avoided outskirts of Bromley and parts of East Dulwich, clutching permit (8)
7. Wild basset is one of them (6)
8. Old train company – intermittently viable – supported by railway kickbacks (7)
9. Protection for consumer, one in bed & breakfast (3)
10. Brace for change – you reportedly head for Boötes or Ursa Minor (4,3)
11. Stealing rude slogans (3,5)
12. Pause in activity of Napoleon director, with unknown in place of le général, at first (8)
13. Decline section of web browser (3)
14. Vessel holding olden-times animal (6)
15. Upcoming refit covers toaster’s top loaf cover for Cockney (6)
16. Force to make awfully big ’ole (6)
17. Film Björk’s initial self-declaration of sexuality (5)
18. Theatre awards, not new, for plays (4)