Oh dear - my old website host who were excellent were bought out and migration is under way. So far so good - Nominet mailed me to say they'd registered the transfer and the website just came back on line.
Now I have to learn how to use a different access panel, or preferably get my elderly Win95 FTP program connected.
[added] The FTP setup was not obvious, but I just needed the existing ID/Password with a mystery address. And WS_FTP is still working.