erm - well - depends what you define as 'really oldschool'
starting in mid 1999 myself i don't think that i really was able to focus on 'celebreties' of that time, but i surely remember Riva, since he was one of those people that gave me regular adrenalin-rushes, esp when i was mining.
He was definitely an 'oldschool'-PK, even camping the little house i shared with a good friend at the road to Vesper east of the Britain Swamps. No idea if its the same Player you are talking about, Jack, but i doubt it to be honest. Apparently Riva was one of the first Characters of a player that then was a Member of I-C for a long time and i have now idea if he is still playing (If you read this, feel free to comment or get in touch with me ;-)).
I remember Sheepdog from the Bounty-Boards of that time but if i remember right i never saw him in game. XLordX was also on those Bounty-Boards, but he was not so much a pure PK but something like a very early PvPer. He loved challenges and he was very skilled in fighting other players. He was one of the founders of the Ancient Oak Community and he was also its main guard, leading to a remarkable save spot in the wild lands.
Since he was a good fighter, he became an andmired and hated PvP celebrity guy, leading to a lot of imposters, that made charakters of the same name - maybe its one of those imposters that Jack is talking about - doesnt sound at all like the old XlordX that i met in game those days!
Then i think one of the Posters of this thread also meets the specifications of an 'oldschool'-Player, don't you agree Mr. Brokenhelm? *
smiles and winks*, because what would us weak citisens do without the protection of the brave fighters, who hunted those feared Murderers, may them be called Seanius Flay or Brockenhelm
I also agree with Brockenhelms list of other 'oldschool'-Players, though i am not sure if they all would like to be mentioned in a thread that so far mostly refered to PKs
Lord Ulysses should also be mentioned, since it was his Katanas, that helped me to earn my first decent gold in those days, not by using them though - i bought them at his shop at Deepwater and sold them at britain forge and other places with a 20% profit
.
I also may use this opportunity to point to my the entrance-showcase of the Museum for Common Britannian History at Castle Finstermoor - there is a book and a Bulletin-Board where you can read a bit about the PKs of the Area between T2A and AoS and also leave your comments if you like ;-)