Hi Art, yes the pinched shape that Ed is talking about is a little difficult to see, here is a zoom in on it:





That thing that looks like a little dimple there is a spot on the surface where the surface normal is shooting around kind of chaotically in a very small area. Such things are bad for generating surface offsets. Making an offset is kind of like taking a stick and running it along the surface and making a new surface at the tip of the stick. It kind of magnifies surface anomalies like this.

One way you can get better surface quality is to build an extended surface initially that has 4 distinct corners and then trim away an outside outline, rather than making a surface with "poles" in it like you have here.

- Michael