I'm interested in a .PGP file. I saw it on the picture and it was called BlueMatt.pgp and we know that the .pgp file is - a security key or digital signature file which can verify the user identity so I tend to believe the BlueMatt is the owner. He has a blog on bitcoin.ninja : https://bluematt.bitcoin.ninja/about/
There I found his Twitter and sent him a DM.
I tend to believe that he is the original owner of the hard drive, let's see what happens...