The stripes on the fenders are team stripes not rookie stripes. Rookie stripes go on the rear of a racecar so when coming up behind one you will know there is a novice driver.
Widths vary. Look at any book that shows original Cobras in race dress and you will see a variety of configurations. Just choose one you like. I use orange racer tape which is about 2" wide.
As far as the rondelles I originally used 16" ones from Finish Line but now have a set of 15", with the trim ring, from Squires Design.
Roscoe