I have been playing with various vintage finishes some are completely new to me some I had used before on muzzle loading rifle and pistol stocks
Red Root Oil: This is actually linseed oil colored by alkanet root and is the traditional finish applied to English Shotguns by Purdey and others and imparts a reddish-purplish-brownish tint to wood especially walnut (but it looks really good on yew I think darkening the heartwood). It is available from multiple suppliers each with different recipes, and probably as many variations as there were gun makers, but I make my own by soaking powdered alkanet root in artists plain linseed oil. Some people use boiled linseed oil (which isn't actually boiled but has metallic driers added) but I think the plain oil penetrates better
Saffron Oil: Again this is actually linseed oil but this time colored by saffron which is a spice and imparts a lovely golden yellow with orange tones. I make my own by soaking saffron threads in artists plain linseed oil
Stand Oil: This is actually polymerized linseed oil, or rather linseed oil that is made by heating linseed oil near 300 °C for a few days in the complete absence of air. It has the consistency of honey and dries a little better than plain linseed oil but not as good as boiled linseed oil. However like the plain oil I think it penetrates better and forms a better finish
Hardener: One of the traditional stock finishing techniques was to apply coats of hardener after the first few coats of red root oil were applied. I make my own hardener by mixing cobalt drier with pure artists turpentine. After allowing the oil finish of choice, usually a coat of red root or saffron oil once a day for three or four days followed by a coat of stand oil, I apply this which essentially converts the oil in the wood to traditional "boiled" linseed oil, drying and hardening it. I then alternate coats of oil and hardener until I have the finish I want.
Damar Varnish: Damar, or dammar, gum when dissolved in turpentine and heated makes a clear varnish that dries hard. Unlike shellac, which dissolves in alcohol both before and after curing, damar varnish, once applied, polymerizes hard and will no longer dissolve in turpentine. It is mainly used in varnishing oil paintings (since the early 1800's) although it is also a component of many violin varnishes. I use the pre-made artists kind and use it as a final finish
Saffron Damar Varnish: Simply regular damar varnish which has had saffron threads soaking in it. It makes a very bright yellowish tinged varnish
Cobalt Drier: I use cobalt drier in my hardener mix but it can be added to any of the above, sparingly, as a drier. A little of this goes a long way I tend to measure it in drops
I also play with the above mixes some for instance soaking the alkanet root in turpentine and then mixing with linseed oil seems to help bring the color out with the final mix being maybe four parts oil to one part turpentine
