Hi BigAl3D,
Thank you for a quick hint
Yes, it worked very well with Volume Builder and Volume Mesher.
With Voxel size of 0.1 cm it actually comes out smoothly enough without the need for Bevel.
Trade off is that it is about 156 K polygons..
Trying to increase Voxel size, but this destroys the shape of object. So almost home...
Have a nice weekend.