M. Longuet-Higgins was the inventor of Rhombo blocks. I checked Rhombo blocks after I got accessed to the internet (see the picture below) this morning. Indeed, the magnetic design of this toy is probably similar to the "ball of whacks". I guess that the difference is the shape between the two mainly. I am curious about who invented this kind of design first.
Again the Rhombo block is quite expensive, though.
One can also build a Kepler ball (Rhombic triacontahedron) using Rhombo blocks. Based on the following picture, it seems to me that only 10 blocks are needed.
