reading his posts, it looks like he may have bought some hotel certs, although he never reported back if/whom he bought from. the seller of the certs would likely know his name and basic info as he was prob booked as additional guest.
either way, if this is confirmed, you can let him know that you will be releasing his info so that others dont get scammed.
that may serve as an incentive for him to pay u back
at least u can find out his community/affiliation and see if anyone there can help u
also, you should release his initials and area code... something to help others in case he has multiple profiles
good luck and sorry for your loss- hope he pays u back