Your bra size, of 32DD really only very generally influences your corset size. First, a corset doesn't have "bands" so just toss that out. A corset is more about the difference in sizes between the different body areas than strict numbers and sizes. If that makes sense. And anyway, bra sizing is relative to overall size, so the A-DD designators hold vastly different volumes dependent on the band size. For example, the 32DD is actually the same volume as the 34D, the 36C, the 38B, 40A, 42AA. The only difference between all the above sizes is the shape
of the cup and the band length. Which is why no one can pick the correct bra size. But with corsets, the A-DD designators all hold the same relative volume, regardless of the overall size. Meaning the 32DD is the same added bust volume as the 40DD, it's just bigger in the body. But the reality is the bust on a 32DD person is about 1/4 the volume as the 40DD. and this is where the confusion really sets in. So what does all this mean? It means that the 32DD person may be larger or smaller, but will be determined by your waist measure added into the mix.
So, now that I have made the whole thing horribly confusing, let's choose your sizing.
Although, once your ignore your bra sizing, it's really pretty simple:
Start with your waist, and say that 24-25" is comfortable for you. Which gives size C waist. Now, you say you have a 37" bust, so if we go up the C column to 37". We find the Size C, cup D is 37". Perfect. Now we just need hips. 34" hips would be Size B. This corset has rather large hips, so the smaller size will still have plenty of room.
Bust: size C/cup D
But, now you have to deal with shortening. The side length given in the chart is you total body length from high into your armpit to the waist. The corset itself will be 1" shorter, or 8" as drafted in the pattern. So my question is, is the 7" the length of your body, or the length of your corset? I would hate for you corset to come out too short. For figuring out the best place to shorten, I think a quick mokup would be best, and just see where the different parts of the corset come too. You will most likely have to shorten at the top, the bottom and the middle to get a good balance.