I too have been in search of old players (old w2 ropers for
www.wormsroper.con) I'll tell you what has helped me.
1) youtube videos about roping.. it's possible someone your looking for replied, and you can contact them that way.
2) going onto your old AIM account, or MSN account... I have found 1 or 2 guys on AIM, I was glad to find any to be honest, because no one uses AIM any more.
As far as your MSN goes, there is no longer MSN messenger, in order to contact people through that. But if you sign into Skype with the email you used to sign into MSN messenger, it will sync all your MSN contacts to Skype
3) you can make a facebook account with the email that you used for MSN and ask your contacts from MSN will be shown on facebook, recommending who you may know' or whatever...
4) the way back time machine can be a big help, finding old clan sites, some will have wormers emails, and/or links to other worms web sites for you to search for emails.
5) if they have signed up for TUS, I would most definitely start there. A simple PM to the specific person usually will send a email to them letting them know they have a message on TUS. So even if they have not been active @ TUS in years and years... chances are you'll still be able to contact them.
6) don't forget, with each person you find, to ask them if they have any other contacts! Hopefully if you can only find one or two guys yourself... a snow ball effect will find the rest.. good luck.