Before you go down a path you can't easily get off of: ditch the saucer and remake it with a base circle that has more sides. Right now you've used the standard that SketchUp gives you -24 sides- which means the result, especially with a larger circumference like here, will look all blocky. Instead, select the Circle tool, click somewhere, move your mouse, and here comes the important part: DON'T CLICK YET! You can now input a number followed by s (for example, 96s) and then hit [enter] to set the number of sides the circle will consist of. I usually work in powers of 2 (24, 48, 96, 192) to get an even result. Remember: every circle you make from now on will consist of that many sides. Great for large scale, not so great for small scale. You don't want to have a screw with so many sides. This trick only works before you execute anything that edits the circle: a Follow Me command, a scaling, really anything and you can't edit the number of sides anymore. That's why you need to restart while you still are in the starting phases of your design: if you add windows and other details, you might not want to rework so much anymore and I'd say that's a shame because your design is pretty funky.