What was the filesystem of the old 60 gb? It can't be ps3 compatible, you need to format with START-SELECT, reinstall the exact same firmware you were on and only then you'll get the region settings and language menu from which I'd recommend you choose the exact same region as this locked dvd of yours. Don't worry about your files, they'll be safe and sound in your other hdd.
Exactly, only after formatting and reinstalling firmware with START-SELECT from recovery menu that he'll get to reset the region of his console. Of course, it's better to use a spare hdd to test it first, then if it works all he's gotta do is backup his current hdd, redo the process, ftp his files back to the newly set console and rebuild database.
Just to be sure, I tried this again with another HDD, a 320gb one i had lieing around, did everything you said and it still comes up with "This disc cannot be played, The region code is not correct". I can't do anything about it, the only way the region lock is going to be bypassed is if someone like Joonie or Habib or [Insert good dev here] is gonna give a shot at cracking the dvd region lock.