It was about time someone use this scan....I used this scan 6 month ago and after that no one else ever used it -_-...while in this scan C.C has her best pose and sexyness.
Back to the wall there are something I would like to point out: first I wish you had used shape layer method for vectoring...anyway,Lulu's vector looks quite good but for C.C vector you could have used some Ideas like using the same color to line art hair as you used for body or a color closer to that(I remeber in scan they were nearly the same color).u know body's line art is black while it suddenly mixed with green line of hair(Green or whatever)and they just dont match and its kinda distracting since black stands out too much.its like this in someother parts of the vector as well but not noticeable.also you could have used more delicacy and detail on neckless and braclet things on the hair(sorry dont know the name )...the colors of C.C are kinda dead,u could have used match colors or color balance option(If your using photoshop) to make the color more lively.
oh I just noticed that C.C's mouth looks strange and it should be stretched abit more.(I have seen the origial scan and kinda memorized every single detail XD)

other than these you have done quite nice and the light effect and sky BG fits it.

Sorry for this heavy CnC and hope your not offended ^^(just wanted to help with your work)...Its just that I'm abit too sensetive when it comes to C.C and wanna see best works of her.