A kind commenter noted that the downloads on older posts were giving “site not found” because they were downloading from “http://roger.local” instead of “https://www.roger-pearse.com/weblog”. I think this is now fixed, but shout if any links do not work. My apologies.
In case any other blogger is interested:
The cause was the rubbishy import/export process for the WordPress software. When I had the cyber-attack last year, I exported the whole corrupted WordPress database to a local database to work on it. The import process must have “helpfully” (and silently) changed all the internal links. I’ve run a SQL script on the live database, and they should all be OK. The moral is never to use the import/export – always work with the raw database import/export.