Parametric two-part cable spool (FreeCAD) - stl size 80x40x30

Remixed version of remixed version.
I had to do it to fix a gap beside one flange that is in OpenSCAD design, and to keep all my files in one file format. Also the flaps are centered now for easier assembly.

STL's size is:
80 mm - outer diameter;
30 mm - inner diameter;
40 mm - spool width;
2 mm - wall width.