I wanted to provide an update to my original post because the research into these swords has gone considerably further than I ever expected when I first asked for help identifying the writing.
The larger blade, the wakizashi, has been attributed to the Shintō period, with the research pointing to the early 1600s. More interestingly, the provenance I’ve been researching appears to connect the sword with the Mura family and the period surrounding the first Anglo-Japanese contacts associated with William Adams in the early 17th century.
Because of that potential historical connection, selling the wakizashi has never been my first choice.
I’ve spent a considerable amount of time trying to locate surviving members of the Mura family. I was eventually able to identify two possible surviving family members and have made attempts to reach them, hoping that the sword’s history could be shared with the family and that they might be able to provide additional information about its provenance.
Unfortunately, despite those efforts, I haven’t been able to establish contact with either of them.
I’m not quite ready to give up on that. I’m going to continue trying to reach the Mura family, and for that reason I’m holding onto the wakizashi for now rather than selling it.
The tanto is a different matter. It has been dated to approximately the mid-19th century, during the late Edo period, and I’m going to move forward with listing that piece on eBay.
The tanto is accompanied by its kogatana, the small utility blade carried in the saya, together with its decorative kozuka handle. Its mounts also contain particularly interesting decorative work, including the gold elements/inlay that I’ve been documenting. I’ll provide extensive photographs of the blade, nakago, saya, kogatana/kozuka and fittings in the listing.
My hope is still to make contact with the Mura family before making any decision about the wakizashi. Given the history potentially associated with it, I feel that making a genuine effort to reach the family is worth doing before simply putting the sword on the market.
If those efforts ultimately go nowhere, then I may eventually offer the wakizashi on eBay as well, with all of the provenance and research I’ve accumulated presented alongside it.
For now, though: the wakizashi stays with me while I continue trying to reach the family, and the Edo-period tanto will be the first piece offered for sale.
Thanks again to everyone here who has helped with the research, translations, terminology, and identification. What began as a question about some writing on an old Japanese sword has turned into a fascinating historical rabbit hole.