I noticed in re-reading the wikipedia article on Dalek variants, that it was the Mk II Dalek that they enlarged the fender to hide a tricycle arrangement of wheels beneath it, not the Mk III Dalek. However, it notes that the small upright panels that circle the middle of the Dalek's body - where the weapons jut out from - was introduced with the Mk III Daleks - before that Daleks actually had two solid bands of metal ringing their body at that location - something I had never really noticed before - especially since many of the Dalek episodes from the First/Second Doctors don't exist anymore (footage lost, destroyed, or recorded over by the BBC).
I don't think I've seen any miniatures that have that original ringing - they all seem to have the verticle slats. http://en.wikipedia.org/wiki/The_Dalek_Invasion_of_Earth has a photo at the top of the page, on the right, that shows the original metal banding of the Dalek 'shoulder/torso' section, and lack of the slats.
Anyway, since I take a bazillion photos of minis, I thought I'd stick another shot on here, showing the two Commanders beside each other. I took this shot a couple times, and each time the left Dalek was slightly out of focus, but I gave up and kept this shot, as it is the most in-focus of the photos I took. Still working on my Dalek Warrior 'drones'.
LEFT: Dalek Commander RIGHT: Dalek Saucer Commander