the C and F fenders are very different. the F has an LED light bar tail light under the fender, the C has a traditional bulb light on top of the fender. the F is a straight edged fender, the C has a curve to it that wraps the tire.
the F also has a digital dash cluster, dual exhaust, vs. the C has an analog speedo on the bars and the idiot lights on the tank, and a 2 into 1 exhaust.
and lastly the F came out mid-2005 so if yours is a 2004 it is not an F.