This stock looks excessively red, to the point where I think the lighting and the photos are affecting the end result. Maybe I'm wrong, but it sure looks seriously red and I've not seen a Beck rifle this red previously.
It's also difficult to determine here whether all of the red is in a varnish/finish, or if some is in a stain. Given that probably 90% (at least) of all surviving guns have been refinished or otherwise fooled with, it's likewise very difficult to determine - if not impossible - if a finish is original just looking at internet photos. Someone with the rifle 'in hand' would be in a much better position to make such a determination.
I no longer think most varnishes this red were made with madder. In my opinion, it's not nearly light-fast enough to survive 200+ years while maintaining this degree of color, unless it's been in a closet the entire time. Given the percussion conversion, this rifle was used. There are methods of precipitating iron oxides that can yield colors ranging from brown through red and even a dark yellow, and the particulate size can be fine enough that they are essentially transparent. They are also about as light-fast as one can get. Anyone can get some of this themselves simply by super-saturating an aquafortis solution while making it. The leftover 'sludge' can be used in this manner once dehydrated, and it is of finer particle size than anything you can grind. Bill Knight and I discussed this years ago and he can offer information on the technical side of it.
If you don't want to make it, Kremer sells it - they list them as "translucent iron oxide" pigments in various colors. One or two European art supply companies also supply it in tubes already mixed with oil but it's best to buy the dry pigments and mull them into oil or oil varnishes more suited for gunstocking than artist oils. With the right proportions of pigment to carrier, you can get a red varnish this red with a single coat over a stained stock (aquafortis stain) or about two coats over a stock sealed with various sealers that will create an amber undertone. It will be as transparent as madder without any of the fugitive drawbacks.
