Hi Gary,

> Is there a way to get a rounded end without a flat spot as I now have?

You'd probably want to incorporate a rounded end more directly into your original curve structure to get that.

I'd probably try some steps like this:

Start by drawing a 180 degree arc which will give the rounded end shape that you want:



Now draw in a curve for the side shape:



Mirror that and draw a line connecting them:



Now Extrude this to make a solid out of it - extrude it a ways further than what you need for the final shape because we'll cut off a portion of the top piece to give it additional shape:



Now go to an side elevation view, and draw in a new curve that divides the extrusion into 2 pieces and has the additional contour that you want:



Select the extrusion and run the Boolean Difference command, use that side curve as the cutting object, that will slice the extrusion into 2 pieces:



Delete the top piece. Now select these edges:



And fillet:




I've attached a 3DM model here with that result and the curves I used in it if you want to experiment with those.

Hope this helps,
- Michael