I did alot of work on this today
ive almost finsihed one face, but these corner pieces are huge. It will take me a while to design them, until then, no pictures. The parts i have done, arent filled with milliput yet. I am waiting for the corners, and ill mix up a big batch of milli for that.

Ive found for things like this, the buildup pieces are best made from Meffert's 3x3. It has very thick "walls" which make a sturdier puzzle...