Fill in the cannon lines, but don't add the lines as you have shown in red, there is a square panel set back adjacent to the wheel bay, will post a pic of this tomorrow for you...and the shell ejector port is ok as is..
This is one of the things I really love about modeling. You start out building a certain aircraft because you see a picture of it that struck you, or you see a decal sheet with a cool paint scheme on it, and soon you are doing research on it and learning a whole lot of stuff you didn't know before!
Yes I had few books in the car which I take to work for reference, 109 for BoB build and a couple of IAF Phantom books for the Cold war build...plus the models!!