The best advise I can give you is to get some videos and watch them. What you are about to undertake is a job, I have been doing it for a few years and I still take 10 - 20 hours. If you don't have the experience and tools, your first attempt may prove very frustrating. First, I hate most Van Dykes forms, there are things about them that I just don't think are anatomically correct. In the Van Dykes catalog are the ways to measure A,B and C.