It's a shame that you had to learn the hard way that Boiled Linseed Oil as a stand alone stock finish has never been a great choice. It is soft, as you have seen, and it offers very little protection or resistance to moisture. The best thing about BLO is that it is cheap and readily available. With care and patience, it can give a nice looking finish, but it will never be a great finish for a gun that will be used. A good coat of wax can protect against moisture while it lasts, but wax is also very soft. The wipe on poly you mention is at the other extreme, and very inappropriate for an 1870"s vintage gun.
I have no idea what finish was used on 1870's Charles Daly guns, and even if we knew exactly, it could be difficult to recreate that finish perfectly today. The varnishes available today, for example, are very different than the copal resin varnishes used by gunmakers over 100 years ago. Many so-called Tung Oils on the market are not Tung Oil at all. The claims very often do not match what is in the MSDS. There have been a lot of Stock Finishing Threads in the Do It Yourself Gunsmithing forum over the past several years. Some of the information found there is helpful, and some is pure 100% crap.
There was some good information in this thread if you can get past the fact that the original subject matter is nothing but linseed and sunflower oil with naptha and metallic dryer... cheap ingredients at an extremely high cost per ounce. Yet some folks remain enamored with it:
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=561049&page=1In that thread, I recommended spending a few bucks to buy a copy of "Understanding Wood Finishing" by Bob Flexner. There are many other sources for good information on wood finishes, but I have not found any single source with as much good information, to help you sort fact from fiction. I see a lot of used copies available for under ten bucks.
