Cryptic crossword

ACROSS 1. Quick comeback from priest may have nothing in it (7) 5. Craftsman isn’t a RA, though he might be (7) 9. He gives one a reason to motor around via Exchange (9) 10. Passenger ship coming from the River Nile (5) 11. A straight-edge for the person on the throne (5) 12. On the bank one could see diver rise to it (9) 13. Is mistaken as to Nero, or use made of it (9) 16. Improve one’s mind, otherwise deify it (5) 17. Invest one with some forgotten dues (5) 18. First two climbers on highest mountain are the most astute (9) 20. Dance written out with a red quill (9) 23. The Musical Times (5) 25. In one would go with Mr Jones the architect (5)26. Make me tour bar in a garden of trees (9) 27. How to make one peer without narrowing the eyes (7) 28. It is allowed, indeed, to be crossed out (7) DOWN 1. Pity about the code! (7) 2. Plate made of part of a flower (5) 3. Even cares about cut-off pay (9) 4. Go on the stage to put one’s name down (5) 5. Person on the make arrives and sets it out (9) 6. Roofing expert is a door-keeper for the freemasons (5) 7. Tender vine is set differently (9) 8. Where the young may be surer of entering New York (7) 14. Nuclear energy in a road, it might appear (9) 15. So tall, ice like this will swing to and fro (9) 16. Sort of college of voters (9) 17. Male address to which queries can be directed (7) 19. Was lightly cut according to merit: MD arranged it (7) 21. Lozenge shape used in a particular Homburg-hat (5) 22. Be in the wrong bed when the tide went out (5) 24. Met when about to turn up a choral work (5)