Rivkin

Its one of the things which are very hard to value. The carving is relatively modern. Probably no earlier than shinshinto. I like it, I find it attractive, but many will have issues with the execution. Its out of polish. It has butchered nakago and nonsense signature.

Every established collecting community with items at high level has either individual or collective appraisals. With top tier paintings there are institutes dedicated to specific artists or schools and you are expected to submit a painting for their consideration, unless its already well known and published. Sometimes there is an alternative when there is an individual who publishes catalogue raisonne than you send the painting to him and he writes back description and whether it will be included in the next edition. Until 1960s museums in general offered opinions to anyone inquiring, now its considered unethical to do so because museums are trying to separate themselves from the unclean world of money and also avoid any controversies. There are countries like Russia, to lesser extent China, and many others in Asia where there is a government certified expertise in regards to any "weapon" that might have cultural or historic value. Overall estimation and valuation is approached with far lesser hesitation in Asia compared to Europe. There is no concept of "equality" but rather you are always facing your grades, class standing, achievements being publicly catalogued and displayed. People are very forward about perceiving themselves as X seat in their profession. If someone says "I am 45th grandmaster in chess" he is from Asia. Other people sometimes say "I am top three" or "top five", but everything below is vague and flexible. In Asia assigning levels to any work, including artwork, is very natural by comparison, and constantly submitting pieces for appraisal is a norm. If you a "writer" it means you got 1st prize in at least two of first or second tier competitions. Otherwise you are just a person who writes as a hobby.

I don't really kantei shinto well, so all is basically a guess why it could be shinto. Its a bit heavy for its nagasa, which might be a hint to shinto, but it does look like a heavy type of blade. We've seen substantially more Owari NBTHK judgements recently for anything that includes a wide suguha. Famous story TJ Go who've been Owari for a long time until it got TH Go and then it was a smooth sailing forward. Roundish-well-defined gunome can also be seen as Owari-shinto trait. There is a tendency to go shinto if jigane is zanguri with mokume elements, which one sometimes sees in Owari though not as often as in Kunihiro-Kunimichi.

I would guess its a type of hamon popularized I guess by Tatara Nagayuki around Kambun. Quite likely from the same period or slightly later.

Many Asian countries have zero weapon ownership tolerance and therefore have goveenment certified “experts" providing expertise and assigning status such as indigenous art, cultural property, cultural treasure etc.. Juyo and TJ are natural analogues of government rankings, which are also common in Asia. To the point that S ranked item has to have at least that many hotels next to museum housing it etc etc. Japanese system is probably not the most formal in the region by many metrics.

Sort of feels like authentic Bizen[???] Osafune signature which is almost gone. The blade can be early-mid Muromachi.

For the tanto I agree with Reinhard that jigane has more rough Muromachi appearance and Uda is worth considering, even though I would prefer long to see long kaeri on Uda. Still think Tosa Yoshimitsu is a good option, and it might be that in hands the blade looks better which would open more appreciate possibilities. On the last blade the main problem it has a lot of sori, so it can't be daito Kamakura blade cut down to waki. It can theoretically be slightly shortened kodachi, but those usually retain sori in nakago, this one does not. It has some interesting utsuri, well formed nioi-guchi... It might be early Bizen, but I am much more comfortable with very end of Kozori, early Muromachi, or frankly - Kaga, Muromachi.

Taima would tend to have fine itame, here jigane is coarse masame and o itame. Shikkake would have periodic gunome, this one has none. Nie activity in hamon is strong, which typically argues against Mihara, Hokke and other Yamato-derived schools. Kaeri is quite short, which would argue against Muromachi period, sue-Tegai tends to have long kaeri. On the other hand if kasane is thick this could be Tosa Yoshimitsu, whose Muromachi generations can have shorter kaeri. Maybe Yamato Tegai, earlier, or Tosa Yoshimitsu, later...

All judgements rendered in 1970s had a tendency to be optimistic. Today's judgements are often pessimistic. It ebbs back and forth, as it usually does. There is some tendency in nihonto community to see the "green to modern" papers transition as a seminal and unprecedented event, but in my experience this is hardly so. My grandparents both collected at reasonable level (violins and firearms respectively) and many relatives wrote "papers" of their own. One had to change his signature entirely, realizing he missed a very prominent series of fakeries. So he disavowed the old signature on such pieces and would generally indicate the need to rewrite other appraisals because the research had advanced in the meantime. But after being burned with those fakes, and more concerned at this point with his reputation, his late writeups have acquired a reputation for being very conservative to the point few actually opted for the "new signatures". In the end blue papers are upper grade judgements from an optimistic period. They can be off, but seldom really raise eyebrows. Koshirae judgements quite frankly have a tendency to be insufficient to begin with, to the point of listing the motifs and not really qualifying who and when made the piece... Also, a very strong contributing factor is that for high value pieces an attempt to repaper would be natural and therefore "green and high value" is a red flag not so much because "all green were bad", but because the "good ones" were repapered... Which in case of koshirae with no specific high value attribution brings a question - what exactly would one expect them to be repapered to? Its often a very generic attribution, blue simply means the piece earned some respect...

Yamato Hosho, tegai (most likely) or naminohira. Not sure about kamakura. Could be Muromachi.

Smartphone in hand it feels akasaka senjuin mino. Datewise late Nambokucho or beginning of Muromachi. Mune does not match, but everything else looks good for it....

I have discussed it a bit in the Guide, but generally if you see one of those with say Kaga Muromachi blade, they are reliable and the blade itself is often good grade because those were not dished out in huge quantities. If you see it with very top name, the modern judgement was obtained and was 1-2 grades lower. Blue papers are never crazy, they can be optimistic... or the modern team could be pessimistic, or even plain wrong.

Its Katana mei and not really Aoe looking, so Kamakura is probably off the bet. The signature is written confidently, without pretense and without hesitation. Can it still be fake - sure, but such a rare name anyway... The style looks Bizen. In principle at the time Kaga and Bungo also did Bizen styled pieces. Bungo works are quite rare and many are center signed, nakago finish is a bit... different. In case of Kaga in particular such nijimei looks viable, as is nakago. So it could be unlisted smith - either Bizen, most likely not from "mitsu" mainstream, but one of the last Kozori or Omiya lineages which tend to be less understood, or it could be an unlisted Kaga smith, which might overall be a better match. Regarding the date I would not focus on Oei specifically.

I like what I see but i am away from books. Does look like early Muromaci Bizen and i personally would be a bit more comfortable with 1440. Signature is well done

There are plenty of activities, but the only way there is such a significant difference for a blade seen from above with light on a side and seen at an angle is if nie is below certain size... or there is a huge polishing issue. The latter should not be the case here, so nie size is small.