The boundary cell of the Schwarz-P minimal surface is made up of 6 patches from Python.
The pair of parch surfaces from net Patch pair (P1 plus P2), are revolved along line from pinwheel center to a cube edge middle.
The new pair of surfaces is then axis rotated 120 and -120 degrees, with line from M1 through M7, centered on pinwheel centerpoint.

Not done yet:
It is easy to see how 8 boundary patches create the 6 holed unit cell of the P surface.

- Brian