Fortunately I
had local copies - stamp scanning and
post-scan cleanup is sufficiently laborious that without the backups, I
probably wouldn't have troubled to redo the work.
If you're a long time WP admin, you have access to the undelete option
on the image page. No need to rescan anything, even if you didn't have
local copies.
Now I do, certainly - this incident predates the image undeletion feature.
Stan