I think there have been two forum resets or purges.
October 2002 and March 2001
From some ancient archive threads I have the following members all joined in or before March 2001:
Rebel, Delta, Ove, Alexbell, Bigsy, fruitbat, MindYerBeak, SKILL, Wedge, Werewolf, Oddball, afraser2k, Oranjeboom, bitboy, Sentient, Grumpy, Unamatrix001
Most of these were probably memebrs before March 2001, as was I. I think I joined late 1999 or early 2000.
Joined in April 2001
Chrisp7, Mint Sauce, Defiant306, John Ross, curiostyx, WiLi GiLl, Terrin
May 2001
x_bit
June 2001
heavy-rotation, FordPrefect, Scuzi, Paras Thacker, heavy-rotation
July 2001
Doobdonk, fixxxer, Bod, Agent-X, Colin S Wilde
August 2001
Kendall, Maz_uk
September 2001
exedanni, Captain Fizz, tom_nieto, Duronboy, LoveableRogue, Dangerous, dazmanultra
October 2001
Balddog, EyeDot, Shak, Chasser
December 2001
Gandolf, Piggymon
January 2002
Matthew-1985
February 2002
Saikul
March 2002
genetic2002
April 2002
mystic, davidmerritt
June 2002
rossi