Using the C gores in the Silverado, with size 20 for the bust/underbust, 14 for the waist and hips and B gores in the hips (total of four) and some help from auroraceleste (thanks again!) getting into it (and the loan of her stiffer bones for the front) I found that:
1. I end up with the same shape I ended up with my altered Dore. But the Silverado is rather more work.
2. I squish out the top of any corset that has the tension I want at the waist. Fine. Next time I will try a separate lace for the top third of a corset.
But not this time. I am done with the Silverado. DONE I say. phooey.