Well, I'm pleased to say that, having shifted the brain fog, I sat down and read the preamble slowly, with my finger under the words, chopped the crossword up and reassembled it. It's done!
Have to say it looks right/better if they're arranged with the 'larger character' reading upside down so they both nominally on the same floor iyswim. Then it's more like the publicity image.
Would that the Inquisitor would yield too, but that's going to take an even clearer head!