I think damascus nailed it in his post # 505376 in this recent thread om stock finishes from the DIY Gunsmithing forum:
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=505359&page=1Specialty finishes such as Timberluxe work well, but $12.95 for 1/2 oz. or $29.95 for 2 oz. is just nuts. Rest assured there is a lot of profit and nothing magical in those tiny bottles. At least the Trade Secret Oils have a slightly more reasonable per ounce cost, but still rather pricey when you consider what damascus wrote about even modest volume production of his own "secret recipes". Personally, I'd avoid the economy version containing linseed oil, especially without addition of a dryer. There are dozens of wood finishes suitable for walnut gunstocks, but the final selection comes down to what you are seeking for a final appearance, and exactly how the gun will be used. Application technique has a great deal to do with final appearance too.
Then there is the important consideration of which finish is appropriate if you are attempting to duplicate an original finish. For many vintage doubles, that may be nothing more than correct application of good old spar varnish, perhaps applied over an alkanet stain. But few people here would ever be able to distinguish the difference between a carefully home-brewed or commercial alkanet stain, and some easily purchased and reasonably priced Solarluxe. And nothing screams REFINISHED on a vintage double like a glossy bowling pin synthetic finish or perfectly filled pores. A final consideration is that if you put 12 different wood finish samples on the same walnut board as a test piece, you will see at least 9 or 10 different appearances. Big difference too, when the same finish is applied very thinned to penetrate the wood surface, or applied thicker on the surface. It's always a good idea to try the finish you are considering on a scrap of the same wood to see if you get what you are looking for.