The center of mass, in rectangular coordinates, is NOT located at (−0.147, 0.015, 0.467) as these coordinates should be divided by M = \pi/4.
You should also be careful about when answers are written as equalities and when they are approximate.
The precise answers are
M_{yz} = - \frac{3 \pi}{64}
M_{xz} = \frac{3 \pi}{640}
M_{xy} = \frac{1903 \pi}{12800}
So the centre of mass is located at (-3/16, 3/160, 1903/3200).