Dallmer Orio replacement for threaded sleeve

I had to design this part as the original part was broken and that made my shower drain (Dallmer Orio) to leak water. I tried to get an OEM replacement, but the newer sold parts did not fit, so i decided to model my own replacement in OpenSCAD.
Big thanks to Dan Kirshner for his excellent thread library - otherwise i would not have been able to make a fully functional replacement part. You can get it here: http://dkprojects.net/openscad-threads/

After some iterations about the right dimensi