I plan to make an Ork tank. I want a modular version that can be 2-4 types of tanks off one chassis. In my research, vehicles like Swedish APCs interest me. The pic below is from here.
The front plate could swap with the top plate, putting the ring in front for the huge (think short dethkannon from stompa, matching picture above) and big gun (think demolisher) versions, and on top in a turret for the supakannon version. But this hull may not be satisfactory.
I have a few of the old Epicast Gobsmasha, with the smashagun of old (demolisher cannon.) I should consider its layout and frame for the basis of a new build. See pic below from here. (This is not one of mine.)
Of course Epic gave us a variety of Ork tanks based on the same chassic, but with several versions. The pic below from here shows these versions off well, each with a different loadout and name.