Ask HN: Are there any Gömbök blueprints?

If somebody doesn't know what a Gömbök is, there is a great article about it [1].

Anyway, they are up for sale, but the minimum price is 150€, which is a hefty sum for a student. I'd like to make one myself, but I can't find anything about Gömböks except for the site I linked and the official store. No DIY videos, no specifications, no blueprints etc. I'm asking here, because I don't know anybody who knows what a Gömbök is, let alone who knows how to build one.

[1] https://plus.maths.org/content/story-goumlmboumlc