Hi Yenmonger, the quickest fix in this case is to cut the part in half, mirror it, and then Join the pieces - I've attached the .3dm result file as Cannon 39_finished.zip .

Now it's also got exact symmetry, hopefully that is a bonus rather than problem?

Anyway, the model seems to check out and looks to be ready for 3D printing. Let me know if this does not work ok for you.

- Michael

Thanks! The reason for assymmetry was my ham-fisted attempts to simplify certain areas in an attempt to get the union to work.

The restoration of symmetry is most welcome. Many thanks indeed.