What are the alternatives for recovery here? (besides trying to recover disk data with specialists)
You are running ancient, unsupported, software on hardware that has a lifetime which you've probably also exceeded and are not actively testing backups. Its is unlikely you are going to get a positive result without finally spending some time and money by hiring a specialist. Or, just consider the lost data as an expected outcome given previous behaviors and move forward. Or, at minimum, someone who can sit/login to the computer and network setup in question and interact with it - even if they cannot do the disk data recovery they can at least provide a professional opinion.