Quick crossword No 454

Across

1. Goya exercises spiritual discipline. (4)
2. To protest, parlimentarian sits in battered oilcan. (8)
3. Binoculars hidden in paper - keep grip! (8)
4. Found out concealed ruin. (4)
5. Gold and first traces of cobalt disguised plant (6)
6. Gasp! Cars banned from Lancashire, shockingly (6)
7. New criminal, to start, beheading nurse (5,8)
8. Business to follow again? (6)
9. Bump into average guy walking around street light, at first. (6)
10. One follows duty to move around airport. (4)
11. Naively idealistic joke cut short by a rarity, losing its first impression. (8)
12. Every so often, Cheryl accepts recorder in place of rest. (8)
13. Last dregs of drink, for example, south of beer barrels? (4)

Down

1. First trace of overpowering, grim scent (5)
2. In the main, it's a terrible treatment for allergies! (13)
3. Roughly cried, heard as simultaneous notes. (5)
4. Dull, coming up with repeated tune in potentially exposed area? (7)
5. Note expression of disgust at good background for figure of fun. (13)
6. Humour during, primarily, darkness - swell, barring the opener. (7)
7. Clumsy fool starts off odious, abject failures. (3)
8. Revise, angry about the heads of teaching and education. (7)
9. Opera's overture, reportedly dismal - that's anything but the right angle! (7)
10. It comes up in whiskey refrain? (3)
11. Hear man of religion to view quality of interesting gossip, perhaps? (5)
12. Play piano in an alternating fashion, good for deception. (5)