A full backup should be a priority
a look at the bottom of the page indicates the software has not been updated since the 2013 version and a backup, if made today, would be of the older version and include the advertising trash.
so a plan of action would be similar to something like.....
1. contact the owner and aquire the domain (maybe a few emails?)
2. aquire admin privileges or locate current admins in order to make a backup (a few more emails and some research)
3. set up a local machine to cleanup the site before updating ($$, time, expertise)
4. install to a new online hosting provider (the couple of hundred $ mentioned above
5. do maintence and pay bills going forward
right now, the domain is registered....
Expires On 2027-10-04
Registered On 1999-10-04
Updated On 2024-08-05
so there is time to work with the owners, before all is lost.
@glisglis do you see a better course of action?