timo,
Most all of my flinters were either the ketucky style or the eastern mountain rifle types. Most of the stocks were high grade curley maple so I started by using an anoline dye that was used by Holland&Holland (gave their trademark dk red color) but bumped into an old rifle maker down south who showed me how to make small diameter ramrods and do it in a hurry too! Well this man showed me his "stain".....a quart jar about full of kerosene, a handfull of nails (or ya can take a file to the nails and add the shavins, then a couple of plugs of Red-Man......let 'er set. The cool thing about it is the color slowly darkens with age because the chemicals keep on oxidizing.....if ya ever seen a real old rifle, the stocks look damned near black and I believe the early gunsmiths used these "oxide" stains also. Anyway that's about all I know about it.....used it and works pretty good.....especially on curley maple.
Rich