Well, I finished the mock-up. It seems to fit perfectly! Only I did have to change the gussets to a single D size. I forgot to take the...ahem...squish factor into consideration. :P
And I think I may lengthen it an inch, and cut off the bottom an inch. I am slightly longwaisted. I have to cut off the bottom because I'm using the hardware from my previous corset, which was a certain length.12-1/2", I think.
I can't wait for this to be done! I've never really liked making undergarments, anyway!