I would definitely have to build it from different parts.
The problem I have now is fairing (smoothing). I would built the final version using fewer points. The problem I have found is that if do the fairing with fewer points, the shape gets seriously distorted. In fact, I have found that the supplemental data points the original designers add are critical to getting the right shape. Part of the problem is you don’t know which points you can get rid of at the start.
If I were designing a ship from scratch, it would be no problem. But when you are doing a model of an existing ship that people are going to take a micrometer to and compare, you have less flexibility.
If I could do every other or every forth frame and waterline and be able to manipulate them at the same time, I could get away with that. But apparently, I am forced to do frames and waterlines separately (I cannot correct a waterline and have the corresponding frame be updated automatically). So I have to fair with more curves than I would really like to.
I did a beautiful fairing of the stern using a subset of the curves. Going back and forth between the frames and waterlines, I got both sets really fair. Then I built the surface and there were huge bumps in the frame gaps.