Update on progress, currently duplicating the main disk where the original was located. Soon will have two copies of both drives meaning I can restart the process if I fail somehow during the recovery
I'm really leaning towards starting with a tool that scans the raw volume and dumps what should be the full wallet file plus extra bits after. So far not having the greatest success with testdisk but once this is done copying I might try on the backup disk anyway, just haven't been able to make sense of the variety of disk dimensions it has been showing, like which one... Really just to have it scan from all filesystem roots looking for the file seems like what it should be doing.
I will explore the wallet file searcher first I think. At least see how it can be made to dump the possible files to disk