For the longest time I thought that the plates only went up to the upper return rollers with the cutouts. As I was measuring and cutting some styrene sheets that did come out rather nice for a first attempt. I kept looking at pictures of this armor plate and noticed in this picture from this angle on this particular Sturmi it really looks to me like the armor plate goes past the return rollers, above the tracks on up to where the lower hull meets the upper. It kinda makes more sense that way too.

http://www.andreaslarka.net/ps531044/53104428.jpg