Parallel Penguin

I'm designing a model starring a penguin. I want the model to taper slightly from bottom to top. Normally when I'm laying out a part on the computer (using Illustrator) I would be able to use parallel lines as construction lines. To make the body tapered I have to use concentric circles as the horizontal parallel lines and radial lines as the vertical parallel lines.
In the picture, left, you can see how the body part was constructed. The blue/grey lines were layed out first and the body constructed over the top.
In the picture the complex piece is the body, the piece top left is the body front which wraps over the top of the head. The smaller wing shaped pieces are the wings.
The final penguin looks cute, keep an eye out for it!