[Andy]

Try running Tools->select-leaky-surfaces on it and see if any areas have holes.


Also try running Object->Optimize-vertices&surfaces and see if anything gets removed.


Press 'n' to check normals are facing out. Another quick way to check is to set all surfaces to 1S (single sided) (control panel, bottom) and spin the model to see if any surfaces 'vanish'. If so, they need flipping - select one surface that you know is correct and use Surface->Unify-normals.

Once you get the objects right, you have a better chance of Boolean ops working but a non-leaky object with correct normals is a minimum requirement.



Looks good - let us know how you get on.