I read about what turns out to be a very useful technique for getting your UV-maps to lay “just so” across a smoothly curved model. I tried it, and it works.
What you do is to start with a checkerboard texture, like the one given by the Tiles plug-in. You then adjust your mapping, by whatever means, until the checkerboard shape flows smoothly across the model. The regular checkerboard pattern immediately shows-up any distortion in the mesh, and also illustrates the orientation of each piece.
(Remember that you must tell Blender to use “UV” coordinates as the Texture input; not “Orco.”)
Just an additional portion to the image to show the distortions of the mesh better. As you can see in the image I posted, there is still some stretching, and it is more noticeable on the numbers in some areas. Just helps you to tweak your UV’s better to keep the stretching to a minimum.
Also helps when the time comes to paint your textures. You can render the model with the reference map from different angles and use the color/number combinations to help position the detail you are painting. Open your reference map in your paint program and paint on layers so it’s always there for referral, save flattened texture files to test on your model.