SteveM

I'm not sure because the resolution makes it a bit grainy, but I think one side is the forging of the sword in August of 1851 by Eiji, son of Gomura, and the other side is the quenching of the sword in February 1852 by Hideyoshi, son of GoXX (doesn't look like Gomura). Anyway, a gassaku. The August and Feb dates are probably just the normal, "traditional" good luck inscription dates.

*The translator has entered the chat* My gut feeling is that the "to mei ga aru" in this case refers to the Koson signature, and not the Nobufusa attribution. The NBTHK attributed the sword it to Nobufusa, so the "to mei ga aru" only makes sense if it refers to the Koson signature. (Meaning: they doubt Koson wrote the shumei. Or, I should say, they have no consensus about whether or not the Koson shumei is authentic). But, I say this without having consulted with either Tanobe or the NBTHK, and it is just a gut feeling.

Often those sites will provide a list of noteworthy families who used a particular crest, but the site I linked to doesn't list any such families, so its a bit of a dead end. But as a side note, family crests were used by multiple families, so its often difficult/impossible to pinpoint a crest on a sword to any one family.

Yours is a combination of the two above. The literal translation is "five-spline fan with three-tomoe, in a circle". Tomoe is the motif of the comma-shaped marks. https://myoji-kamon.net/kamonDetail.htm?kamonName=丸に五本骨扇に三つ巴

Spider web and tree trunk is an often-used design. Here is a thread with more info

Well, I think its more of a spiritual marker than an actual temporal marker, but yes sometime around that date (note that Japan is one day ahead, so Pearl Harbor happens on the 8th for them).

Chinese　大明宣徳年製 ("Made during Ming Dynasty"), but put on a lot of brass items to give the appearance of age/value.

I was one character off. According to the registration card, the inscription is 対米英宣戦之吉辰作 (made on the auspicious day of the declaration of war against America and Britain).

I think we've been here before https://www.militaria.co.za/nmb/topic/47622-silk-roller/

A lot of errors in (what I'm guessing is) that machine-translation of the authentication paper. The authenticating organization is NTHK (not Nihonto Kenkyukai OR NBTHK, but a different organization altogether). Migakiage mumei →　Suriage mumei Itsutsume Chojiri midare ko → Gunome-chōji midare (no "ko" on the end, just a misreading of れ) Nifuki →　Futasuji-hi　(the meaning given is correct, but the kanji and reading are both wrong). Nagasa is 2 shaku, 2 sun, 6 bu (the translation read 貮尺 incorrectly etc... For a machine translation, it has done reasonably well - you couldn't imagine anything this accurate 5 years ago. The technology has become so advanced that it nails a lot of the difficult text, and only gags on the super technical stuff. The problem is that the super technical stuff is what is used to pinpoint schools and smiths. But, I imagine this is also a matter of time. In another 5 years, the level of machine translation and interpretation will be exponentially better.

I think this one's Shoami Ieshige (家重).

皇敵無骨 = Kōteki Bukotsu Enemies of the Emperor/Empire are savages. (Well, the meaning of "bukotsu" is "unrefined", but somehow that doesn't quite work as a slogan when translated back into English, although you can find a lot of web sites that use this as a translation). Even the word "savage" or "brute" doesn't feel particularly impactful to our ears, but perhaps in 1940s Japan this was a profound insult. The other bit on Dee's sword looks like 対米英宣戦之告被作　Made upon the declaration of war against the US and Britain.

Glyphwiki lists 𨸩 as an alternate form of 改 https://glyphwiki.or...iki/simch-kx_t162305 posting as a pic in case the link goes dead.

This is what I have heard as well. My understanding is that artificial stones are consistent in composition, and they give the polisher a much more predictable (hence, desirable) outcome, without any of the unexpected impurities of natural stones.

https://nihontou.jp/...ugu/tuba/1180/00.htm https://nihontou.jp/...ougu/tuba/905/00.htm https://www.choshuya.co.jp/senrigan/干し網図鍔（鐔）　銘　埋忠橘宗義/鍔/宗義 https://www.bonhams....5-1868-dated-1860-2/ https://www.alamy.co...-image391579422.html

Fishing nets, and then probably fish drying from lines.

Shōhei 6, June 1st (1351). Aoi Art has a short description of this cloth (originally leather). I think there might be a couple of threads on it here on NMB as well. https://sword-auction.com/en/product/7208/鎧兜/

Unique Japan mistranslated that mei. It should be 兼松一則 (Kanematsu Kazunori).

臨川堂？　Rinsendō It would be the smith's "art name". But it doesn't quite fit with Shōami, as far as I know, but maybe I'm missing something.

In the case of the Naotane, and in the case of Guido's swords, the pair were signed and dated with the same date, indicating they were made with the intention/expectation of them being used as daisho. Having consecutive registration numbers is probably another strong factor. I think these two things are the main criteria for the NBTHK, although Guido also mentions they should have the same features (the deki).

Historical Armor and the History of the Military Founders of the Ii Clan by NAKAMURA Tatsuo

Or 長光 (Nagamitsu)

Rakutō (East Kyōto). So Kyōto is the right location 城州愛宕郡洛東住 (Jōshū Otagi-gun, Rakutō-jū) but I can't find the smith. I also suppose its Yasutaka 保高, but Wakayama is a bit inconclusive on it. He lists two smiths using those kanji, but doesn't mention location for either, or typical mei styles. He just notes that both are late Edo.

開眼子 (literally, "child with opened eyes") is the "art name" of the artist, Kanezui. The use of "child" in the art name, and the image of the child on the tsuba, is coincidental. The theme of Hotei with a child (particularly, a child in Chinese dress from the Tang dynasty) is an often-used motif. You can find other examples if you search for Hotei with Tang-dynasty Child (布袋唐子). I don't know the meaning or the origin (well, I guess the origin is Tang China).

The perfectionist in me demands I repeat the correction from the other thread. Please forgive: The theme as described on the paperwork is 雨龍 (amaryū, or rain dragon), not 雲龍 (unryū, dragon in clouds).