Is there by chance an undocumented config option to change the wording of the message that comes up when a page is not found in the archive? For instance I would like to make the message say “Archived Page Not Found. Sorry, this page is external to the website and thus not part of this archive” instead of “Archived Page Not Found. Sorry, this page was not found in this archive”.
Not yet, but have received requests to customize this, so will see if there’s a way to do add that soon..