Hi Brian, there are still some irregularities with the shape that are causing problems.

Here's another one - there is a tiny slivered fragment in this area:







You must have had a really tiny segment in your original curves there.

Another thing that I noticed is that the arcs on the inside bottom part are not tangent with the body of the ring, there is a pretty shallow angle in there, and actually it looks like there is another tiny surface fragment in that area, it is probably having difficulty making a corner in that area.

When I zoom in closely on the front view I can also see that your ring has a very slight shift to the right, the profiles were not aligned precisely - I would normally recommend doing an extrude to make a shape like this since that guarantees a very precise alignment along the extrusion direction. Here it looks like you must have done a loft between 2 different curves and at some point there was a bit of drift when you moved the second curve back.

I'll see if I can create a tuned up version.

- Michael