Specialized have changed their web site and I'm struggling to find the archive section.
Drop-outs are looking the killer I'm afraid:
This is a genuine S-Works, listed as a 2005: http://www.togoparts.com/bikeprofile/im ... ll/414.jpg
2003: http://www.togoparts.com/items/images/i ... 900096.jpg
2002 S-Works: http://img.epinions.com/images/opti/2c/ ... -bikes.jpg
Dropouts seem consistent right through to the modern models. It's pretty similar though, no idea what else it could be. Decals don't look right apart from the downtube M5 metal one in Black, the font's just not quite there to me. Rockhoppers pretty much the same dropout too.
Sure you'll be able to tell as soon as you see it in the metal. Got my fingers crossed for you, but wouldn't hold my breath unfortunately.