Like I said, it's more or less impossible with his dropping off the face of the earth (and in this case I've tried even using the typical email/pword he used for most places, to no avail...) and unfortunately, aside from website and forum information I lack anything concrete, though I understand the security reason.
If you want to send the email and wait for his reply (or lack thereof to show that he really isn't around), then by all means, I'm willing to go with that. Hell, if for some miraculous reason he's actually still checking his emails and replies that'll be all the better too.
In the meanwhile, though, it just occurred to me that ownership, while convenient, wouldn't even be necessary. All I really need is to have the server taken off from delisting - the new site URL is the main thing that needs to be changed, since I presume the currently non-working one is the reason as to why the server got taken off in the first place. Is this possible for the time being?