Hi Jens,

I think it was carved from a single piece of stone and ground down and sanded. This technique was not uncommon in Egypt tool and statue making. As for the precision, it is amazing, but hey look at the precision in Tut's funerary mask, the meteorite dagger entombed with him and even the Pyramids - they are aligned north-south with an accuracy of up to 0.05 degrees. A mass slave/bonded workforce who worshipped the leader as a God can achieve greatness!