After searching around the forums months ago like Al suggested, I found this post that user laurent444fr posted back in late 2005.
if you try a search :
webcam boy part
and you will find 14 parts of different videos about him
Webcam Boy - Part 00 -Teen Self Cam.wmv 31Mo
Webcam boy - Part 01 - Dick on a Desk.wmv 24Mo
Webcam Boy - Part 02 - Horizontal Jack.wmv 30Mo
Webcam Boy - Part 03 - Self Suck of Cock.wmv 164Mo
Webcam Boy - part 04 - self suck.mpg 54Mo
Webcam Boy - Part 05 - Self Suck of Dick.avi 365Mo
Webcam Boy - Part 06 - More Self Suck of Dick.wmv 42Mo
Webcam Boy - Part 07 - Left Hand on the Dick.rm 84Mo
Webcam Boy - Part 08 - Face Cum.avi 116Mo
Webcam Boy - Part 09 - Autofellatio (selfsuck).wmv 86Mo
Webcam Boy - Part 10 - Selfsuck.avi 51Mo
Webcam Boy - Part 11.rm 14Mo
Webcam boy - Part 12 cum again.avi 98Mo
webcam boy - part 13 there is no part 13, supersticious ???
webcam boy - part 14.avi 103Mo
He is incredible, I wonder if there is some other videos of him but if somebody has the part 13, I m interested.
He (laurent444fr) then makes a few other posts on the same thread with links to videos
However, the links no longer work. Fortunately, I have found several other videos from webcamboy.
After a bit for searching, I now have parts 4-12, 14, and 3 other videos (part18b, 18c, & 18d.) I am still missing part 13 (as was laurent444fr). Since I've found videos of part 18, 18a is missing and I'm assuming that there are more parts to 18 since it doesn't have any cum like all the other videos. Also, part 18d seems to be named incorrectly since it doesn't seem like a continuing video from 18c.
So for those of you that are left wondering from the pics of my first post, "webcamdude.wmv" is Part 9, "Autofellatio Selfsuck..." is Part 14, and "Webcam boy - Part 12 cum again.wmv" is in fact Part 12.
I have found links for parts 19 & 20, but they are also broken. So if anyone knows where I can find or has more videos of him, please tell me. I will continue to search for videos and I will keep you posted if I find more.