I can understand your not wanting to divulge the specifics of the design, but some general parameters will be necessary. Also, placing a copyright symbol on the posted drawing will provide immediate protection, even if you've not applied for the copyright yet (you would need to apply relatively quickly though).
There are a number of ways to get a digitized model of the mold or the buck, in which to create a point cloud of geometric samples on the surface. These points can then be used to "reconstruct" the shape of the object, digitally. Photogrammetry is the simplest method and used by lots of industries, such as cabinet and countertop makers, so they can get a deadnuts precise fit into existing structures. There are quite a few different approaches to this, besides photogrammetry, some inexpensive, so some research into 3D scanning is order.
You can also do this manually, by taking off the lines, which is an ancient way of doing it, though doesn't require costly equipment. These "offsets" would then need to be input into a modeling or hull design package, so you can get the shapes recorded.
