I am trying to make a series of plugs for some new engine bay parts for my Marcos Mantula. I'm really hope to get some advice on the best techniques for creating complex shapes with some double curvature. While I'm getting close to the shapes that i want it's still not 100% perfect. I seem to be a perfectionist without the skill to achieve the results that I am looking for. Are there any special tools available from anywhere that make it easier to shape, for example, a concave curve with a varying radius?