The book "Frank A. Pachmayr, America's Master Gunsmith" published by Safari Press is a very interesting read. Seems when walnut groves in California and Oregon began to be sold off for development in the 1950's or so, Frank Pachmayr negotiated to buy the trees, all the trees. He literally had barns filled with walnut logs and stumps. I have a friend who is also a German gunsmith who was friends with him, and somehow got some of those walnut slabs. I bought what remained of them when my friend's shop closed, and I still have a couple of blanks cut from them, full of fiddleback figure. I have seen several custom Mauser rifles built by his firm, as well as two Parker upgrades. The work was absolutely the best I have ever seen.