Self-taught, but not without a lot of research and trial and error. I've spent far too much time looking at stock refinishing and restoration threads on military surplus firearm forums. Probably the best resource that I have found yet is the sticky / how to section on surplusrifleforum.com..tons of great tips and info available there (see link below). The "how to do an aged oil finish" thread was used as the basis for the PU stock finish. http://www.surplusrifleforum.com/viewforum.php?f=137 I like using Tung Oil Finish (viping varnish made by Minwax and Formby's) as well on different projects...mainly AK wood. I agree, it's very easy to work with, can be applied to a matte or gloss sheen, gives good protection, and it's easy to touch up.