Started typing almost exactly this comment before checking to see if anyone else had. Absolutely. I guarantee that for any "old hardware" need there's a geek expert selling recovery/compatibility/adaptation hardware. These problems have all been solved, albeit not at a level of "take it into a repair shop" convenience.

Just as a point of general archival best practices: old spinning media are extremely fragile. Your goal should be to image the drive exactly once, before doing anything else. Once that completes, everything amounts to a pure software problem you can solve at your convenience. But insisting on booting that drive repeatedly trying to "recover" it is a good way to break it forever.

Also:

> The internal hard drive uses SCSI with an unusual connector. Adapting it didn't seem straightforward, and we weren't confident the old file system (HFS) would be easy to read from a modern system.

Yeah, that's silly. You can literally mount that drive image on a vanilla linux box.