I might have addressed the problem of the curve facets being so apparent. Somehow I didn't notice it before but the smoothing angle had been set low at only thirty degrees. It's possible that when I last upgraded the SketchUp program the smoothing angle had been reset lower and I didn't notice. I've now reset it to at least ninety degrees and I'll see what difference that makes. If it's not enough of a difference then I'll set the smoothing angle higher again.
This evening I tried recreating the basic shape of the ship (the main section and the ring) with more facets to the curves (180) and a higher degree of smoothing (90). The facets almost completely disappeared when rendered. I'm going to play with it a bit more to try for a more seamless result when rendered and so far it looks promising.
That said I'm not inclined to rebuild the model from scratch. It would take too much time and I'm also anxious to get back to my previous project. I can always come back to this later and I'd also like to make schematics of this deign for the Valiant.