Yeah, I thought Book also. Also considered Quibbles to my other answer but couldn't really parse. Thanks anyway Stevie G, and Seamus.Hope next week puzzle more comprehensible!
Having looked at all the possibilities that ?O?K throw up for 9A, I'm also plonking for WORK. Could be another wasted envelope and stamp (has to be first class from here too!).
Thank you so much for posting the image. My aunt is now 97 and still does most of the WS but when I am not in Glasgow I rely on you to enable me to assist, if I can, with the few that stump her!