He must have taken a short radius and long radius and combined them in 3D design software as you can see here he removed the inner and outed side rails where they cross. Wonder if he designed this for a specific part of his own Layout and figured since he already had in the software why not sell them? At that price there would be a hefty profit but I imaging a very small customer interest base. I do like his thinking and idea though.
![[Image: super-smiley-emoticon.gif]](http://www.sherv.net/cm/emo/word/super-smiley-emoticon.gif)