That takes time and effort, and has legal implications that the archive might not want to deal with.

it's a video game archive. Virtually no video game due to the young age of the medium is in the public domain, so both creating digital backups, let alone making them available is a pretty good way to find yourself in a court with the rightsholders.

I don't think anyone would ever get in trouble for creating digital backups, but yeah: making video games available to the public without permission from the copyright owner is a good way to get at the very least ceased-and-desisted.

isn't technically speaking -a small private group of donors- not exactly -the general public- ?