Thanks to tilbee, perseverer and contendo. I see 32a now. My error was seeing 2 words as a linking phrase, when they are part of the wordplay.
I was aware of one thematic pair being abridged, as it were, but I had in mind another pair, which I'd found on the internet and now, thanks to contendo, I've found in Brewer's (mine is the 17th edition) under a separate heading. I feel that's unfortunate and merited some preamble warning.
At least I'm not in any doubt about the pairings and the final scores, but whether I see what changes to make is an open question. I do see a couple of changes giving an important word. Will press on.