Fireman Tim. I like the pic's of your fullsize "donor" tank...Some beady eyed people have spotted iregularities with you "donor" example. That's how good this forum is. It's full of people that have an amazing breadth of knowledge and you have all of this free of charge.
I'm very pleased you posted the pic's of the fullsize PZIII as I have a few questions to ask. One of them is the position of the return rollers... Is the middle one higher than the front and rear one. Or are they inline and angled down towards the front of the vehicle. I hope this forum can help us with this.
I know I seem to be focusing on the return rollers, but I probably think we both need some help here. I think the way the tracks sit on the tank is pivotal in the way it will look when you have got it finished.

Gigantohawk.