Thank you both. I had forgotten DD and hadn't realised 29 was a person.
I already had the shapes apart from those gaps, but I'd been led astray by one of the clashes, where selecting the wrong letter still gives a total within the multiple thematic sequence. That made it impossible to predict the missing entries based on which multiples I thought were still to be decided.
I get the striking example. Is there also something thematic in the source material referenced in the 10th letters that I've forgotten about?