I know I didn't explain what I meant very well with regard to the cross-sections. It is quite hard to do without pictures. Given my understanding of the rules I put forth, the actual cross section of each gun would be different, but they vary only by the constraining dimensions, mostly set by the major components. There are significant exceptions, but I have seen them so infrequently, I think they prove the "rule". Perhaps, the "rule" exists only in my mind. I would probably have to write a book to fully explain my understanding. A colonial Lancaster and a mid-19th century E. TN rifle look very different. However, as far as I am concerned, once you have the correct lock, barrel and mounts, you use the same tools, procedures, and basic contours to create them. The best example I can give is drawing an oval in a CAD program. That oval can be contorted into all sorts of extremely different cross sections, but they are all an oval. The dimensions of the longest and shortest diameters set the shape of the oval. I contend that it is exactly the same for most gun wrists for example. Now, I realize that some schools do not use an true oval in the wrist, but in my experience, most do. The differences can be very subtle, and you do need to understand these when you recreate certain schools or makers. I still treat these as exceptions or variances from a base line.