I did miss that somehow. Thanks for bringing it up again.
Louie's the one who would be interested in code, so the Wayback machine might possibly be of use to him.
As for off site backups, you've got that right. Stuff happens. I had a 110-story building fall on top of one of my data centers once, Not only did we not lose data, but our business operations didn't miss a beat. Both Jim and myself are rather obsessive about making sure the data is backed up, including daily copies to an off-site location. In the event of a real disaster, PrimeGrid may be down for as much as 24 hours, but at worst we'll lose the last day's results. If you do this stuff long enough, you see this kind of thing happen over and over. If you do it for a living, you're expected to make sure that you're protected against this kind of event because it's a matter of when, not if. The problem is that when you're running things on a shoestring budget that's typical of an operation run as a hobby or a club, it can be really hard to put together the resources just to keep the operation running, let alone to have adequate assets in place to handle disaster recovery scenarios. So let's not judge the powers that be too harshly because it's difficult enough just to keep something like this running.
For me personally, I use a backup system that lets me back up my entire family's computers to the cloud.
As for which files, what I'm interested in is anything that lists test results, meaning the number being tested and the residue produced by the program. I have no idea what Louie might want.
Finally, yes, this is a huge blow. No way to sugarcoat this; it's going to set back this search quite a lot if the data can't be recovered. The only good news in this is that because we decided to split the project between SoB and PG by k's, at least we have all the data for 2 of the 6 remaining k's. Only two thirds of the work is lost rather than all of it.