Gunsav'r Satin on top of Herters French Red grain filler is pretty much the standard of the gunsmithing colleges. No big learning curve or crazy labor expenditure of the old finishes.
I have not heard of any standard and virtually every time and place I have asked has produced different answers.
And no satin or matte finishes should ever be used on a stock. To achieve the surface they add ground silica. If matte they use more and coarser sand. It makes the finish cloudy and weakens it. It also reduces frank water resistance.
And it is so easy to make test boards.
