Rivkin

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.

Very strong jigane, but if one don't see hamon on top-down photos of eirakudo it means its nioi with maybe ko nie.

Thank you very much, that probably it!

I read "ko" followed maybe by tsugu?? Any help would be greatly appreciated. Its an interesting blade I picked up and I will try to post more photos later...

I appreciate the vote of confidence, but I see the same - there are some issues, though shintetsu like this is probably not a great problem here - it does look like a typical sue Bizen in suguha.

With such boshi I would say Tametsugu appears as quite possible outcome.