The 'NRA Gunsmithing Guide' is excellant and Monte Kenneday's 'Checkering and Carving Gunstocks' has sections written by some of the old masters.. The most mathmatical approach is in the book 'Professional Stockmaking' by Westbrook, publiched by Wolfe. The latter gives a very concise and reproducable methodology to producing a rifle stock. Shows grips curvatures, comb shapes, heel and toe clearances etc.. Gives a good idea of how to finish a rifle stock..