It may be tough to find people at this point, as we Kujatans were merged with Valefor about a month ago - and I know of a few people from Kujata who, after we verified someone here had their name 2+ years ago (but have not been active since), were able to retain their name. This means if someone has your friends name now it may not necessarily be them if they quit years ago too.
However, since you left, a website called ffxiah.com sprung up - it lists all sales on the jeuno AH, and its actually almost up-to-the-minute accurate. It also lists people's sales history, so you can see if they are still active (provided they didnt turn it off (most dont) and provided they still use the jeuno AH (which most main characters will)).
To help you out though....
Pussenboots: appears to still be active http://www.ffxiah.com/player.php?id=473712
Carby: Closest name is Carbyte, who was last active late December 2009. carby may have quit long ago too. http://www.ffxiah.com/player.php?id=1134659
Oishii: Seems to have quit in January of 2009: http://www.ffxiah.com/player.php?id=988209
Griffin: Could not find him on AH, he may have quit long ago too.
So your best bet seems to be pussenboots. I wish you luck, sir!
PUP 30, BLU 16
Sozu Rogberry(pre Thf Knife patch): 0/49 ><