Snap-locking sphere container inspired by Demi-sphere

I loved the Hollow Demi-sphere http://www.thingiverse.com/thing:3068 but I was a little bit disappointed when I found out that it does not snap fit and falls apart by itself. So I remodelled it in OpenSCAD and then changed the angles of the cut out cones to get a snap-closing sphere that does not fall apart by itself. The only drawback compared to the Demi-sphere is that the two parts are not identical anymore, but they are still very good for printing as they are both flat on the bottom (the la