I have looked into this. The R6S is a '04 R6. The frame is the same as a '05 but the only difference between the '04 and '05 frame would be the triple trees. The trees on the '05 are different because of the inverted forks. And yes, your motor is an '04 motor. I also don't know why they went back two years, when they shoulda kept the '05 for the R6S. I actually had a nice laugh one day at my dealership regarding the S model. Those guys didn't know **** about it. They said it's basically an '05. I said the forks are from '04. They said, yeah, besides those. Then i looked at th e radiator and saw one fan. Told them. Yeah, besides that. Then i started asking them about the throttle bodies and ****. They didn't know anything. I walked away laughing at 'em.
The front tire is even a 120/60, not 120/70 like an '05.