My old Mac died, and having bought a new (used) one, am trying to read the old startup disk. It's showing in 'diskutil list' as /dev/disk2 but the partition disk2s2 is greyed out in diskutil and won't let me mount. Various articles talk about having to "unlock" the disk before being able to mount it, but that option is nowhere to be seen in diskutil. I can't remember if it was ever encrypted (with Filevault?).
I've attached a picture from diskutil.
I've attached a picture from diskutil.