I also did pattern prep on the Truly Victorian 1903 Edwardian Corset. I think what I will do is do mockups for both and take them up to my Corset Goddess and have her help fit me in both. The pattern prep took an hour just to cut out the pieces. There's more than double the amount of pieces on this corset as there is in the other one and there are gores in the hips and boobs to deal with, not to mention padding bundles for the chest and backside.
All of that, plus the fact that my chest measurement is very small compared to my waste measurement, which means there is going to be major alterations to this corset (and there looks to be very few going to happen on the other one), is leading me to lean toward focusing right now on the 1911 one, which is also technically more period, but I will probably go ahead and at least get a fitting in this one and maybe even make it just in case something else should come up where I need an S-bend corset. (File that under things I never thought I would say.) Also, it is good practice and good knowledge to have. Either way, the pattern is cut out and ready to go at this point.