SteveM

Not water dragon, but "water tiger". December 1842 is as close as you'll get. No specific day is mentioned. December is a translation used for convenience. I don't know the precise start/end dates of the Twelfth Month for 1842. I would use "published" rather than "printed". I somewhat minor difference.

銘□ →　銘曰　never sure how to read this, but most often written in English as mei iwaku. I think only seen on Torigoye boxes.

Poem by the Chinese poet Xie Zhen (谢榛). Hopefully one of our Chinese-speakers can provide an English translation. 花神默默殿春残，京洛名家识面难。国色从来有人妒，莫教红袖倚阑干 https://en.wikipedia...wiki/Xie_Zhen_(poet)

義完 (Yoshisada) is a possibility. This thread mentions Ishihara Yoshisada signed his name two ways 義定 and 義完 (both read as Yoshisada). I haven't found any corroborating evidence for this, however.

Looks like 勝 (Katsu) on the left. It is a mildly unusual family name, but not a one-of-a-kind family name, so Katsu as a surname name is one possibility.

すっきり Thank you Markus. (And well done, Uwe for picking out 披...my mind wouldn't accept 披 or 波 etc... I had the aperture set too small. Need to always look at the bigger picture)

Possible, but I was swayed by the ume branches of the design, and that preconception keeps me from imagining anything else (even if I admit that it doesn't look too much like the cursive form of 梅).

弘寿（花押） Hirotoshi

Can't get it. Maybe someone can correct/guide. The side with the cloisonné should be the omote/recto, and the plain side is the verso. 梅囗囗屋之 にしき登々乃い

Made with Yasuki steel （以安来鋼). 　 Imperial date of 2601 (1941).

Smallish corrections 紺系縅具足右袖　　right sleeve of navy odoshi gusoku 長さ 二尺二寸七分　2 shaku, 2 sun, 7 bu 室町時代の将軍格のものと思われる. 具足の右袖で特に貴重な文化財として筑後国住武藤家に古くから 伝来した名品也 明治参拾貳年春 武藤秀弘 The paper with the kamon says its from the collection of the Takahara family, and the mon is a fan (hi-ōgi) with a tortoise shell (hexagon) border.

Possible to get a picture of the whole tsuba to see how the writing is oriented? Are these lines all on one side, or are they on different sides (recto/verso) of the tsuba?

Yes, that is correct. According to Aoi, this Tomoyasu is the son of Tomonari (友成), who is supposed to have been the origin of the Ko Bizen school (c. 987). Which would place his son (Tomoyasu) around the 1000s (Kanko era, as indicated on the sayagaki). But this leads us down a little rabbit hole, as there is a divergence of opinion about Tomonari. Anyway, without getting into those details, I can only repeat what Jussi says; a blade that appears to be from the early 1000s, that has a plausible signature from Tomoyasu, would be interesting from a historical perspective even if it were retempered. A real unicorn.

I'm curious about the sayagaki. Anybody know anything about the writer, Sekizan? Looks similar to Satō Kanzan's writing.

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).