more stairs

So in looking at the way in which a staircase is made in real life I have attempted to articulate it in graphic form.  

The real problem is that paper is a much more complex and actually not hard geometry but something much more subtle.  

The real tactility of the origami object is really its strength.  Sorry, I am  just finding it strange to have finally have got to the stage where 3d imaging is possible with my level of modelling an it really just makes me look more at the real origami object.