Rivkin

I would think not. Low shinogi the difference can be close to zero. In sue Bizen and a few others. Yamato is a definition of high shinogi. Typically has 0.6 (usually 0.7) -0.75cm kasane so 0.55 is very thin for it. It has shinogi kasane I think often in excess of 10mm but I don't have the books in front of me. So, no this blade does not sound like Yamato or high shinogi, but then its a very secondary information.

Its Edo period most likely, but having full nakago picture would help. Boshi contour is sort of visible but again could help.

I am not the person to talk about signatures, but things about this one I don't like. Still horimono is decently executed.

The way I look at it their crucial mistake is inviting outside people in the first place. Museum world is a place where few have a single serious publication under the belt, but the loyalty ensures even the most creepy things remain concealed. There are specialized departments in Russia where objects slowly rot to nothing with two-three decades, which dispose of "controversial items". For example, instead of acknowledging the location of Klimt taken in 1945 was known all these years, despite being officially "missing", it was sent as "the work of unknown artist" to this basically pool of water storage, in a few years acknowledged as destroyed and delisted. Items sold in 1930s to private collectors can be at any time targeted by lawyers, while there are about seven million storage units taken from concentration camps and related warehouses, which obviously nobody will ever use for an exhibit, but which will never be sold on the open market. In the ME the destruction is simply unprecedented as nearly every single modern country has very little to do with XIXth century borders, so everything related to its accepted history is funded at priority level, while everything else is basically gradually or not so destroyed. Instead of ever expressing mildest concern, university and museum scientists can't shut up about about illegal digs, illegal trade and these items being taken to wealthier countries. You have literally entire site purposefully bulldozed for apartment complexes but the country can't rest because before it was done one tiny statue from there was picked up by someone, packed and sold to a collector in the US.

There is a venue for Japanese government to sponsor polish and preservation of swords in foreign museums and it often does so.

As formulated the problem suggests that the same store has a somewhat generic sue Bizen blade (i.e. not first tier attribution) and long, perfect condition Nambokucho blade... at the same price. This leaves very few options for what Nambokucho attribution is. Probably Mihara or something similar.

I would consider late Muromachi as a possibility also.

I don't think its fake per se, but rather indeed a SEA sword in Japanese style. With 20th century random add-ons to keep it together.

Re: nihonto guide in the signature.

If not for kizu, being tired and so so polish this might be actually a very nice sword. It does not look strictly Hasebe, but generally it is a period Soshu blade.

Wow! Thank you very much!

Excellent blogs by other people, first and foremost Markus, have inspired me to being releasing a newsletter. Three topics each issue, each something not well covered by books. In this one you can find articles about: Kyushu nihonto Saiha and yakinaoshi - same of different? The true meaning of NTHK scores https://www.historyswords.com/news1.pdf

The last photograph looked like Kaga nakago with kiri yasurime. But that just might be the projections/shadows.

There are quite a few suguha Ichimonji, which are .... to kantei. This however does not look like it. It feels like a Muromachi piece, possibly earlyish to mid. These are hard to judge, but I would pivot towards a particularly good example of Fuyuhiro. P.S. I just noticed the nakago. Come one, this is Kaga Kiyomitsu. Not too far from Fuyyhiro though.

Classic shinshinto. Pity its mumei.

Thank you very much! Its a very strange list. There are many rare smiths - Hankei, Horikawa Kunihiro, Masamune. However, if you wanted to see the rarest you would probably ask for Umetada and there is only one Myoju. There is ton of Muramasa (is that an interesting or educational smith you need to see many times to appreciate?), no Hasebe, and something happened with Ichimonji, though some of it have to do with personal names. There is a batalion of Kanemoto and Sue Bizen, but only one Akihiro and Hiromasa each.

Unfortunately for things like this I would start with what it looks like rather than how it is signed. Which requires good photography - overall view, activities etc. These are very basic pictures which don't tell much. The basic theory I would consider is Muromachi wakizashi. Pre Muromachi kodachi is something quite rare, especially from Nio (?) school.

Judging by nakago condition the earliest it can be is late Muromachi. The signature placement is not exactly Edo period's, but then the signature execution is sort of is. Sugata is not very specific, but its not likely to be an early one.

Yes, matsukawa or mokume. I will go further and venture a guess this is either shinshinto (more likely), including later smiths like Gassan, or actually a quality early blade, probably Nanbokucho, in a polish which makes it look fresher. Stylewise its between Norishige and Yamato.

I think its good as is. Mino, late Muromachi.

Yes, its very hard and still much is missing, but just doing a bit of a banter: Mino, end of Muromachi.

But the basic problem of 99% photographs people post here they are taken in the sun during the day with light from above. It needs to be one lamp on a side no other sources of light. With this there is a chance to get what it is. As of now its probably 1570-1600 blade.

Yes, it would typically be wider and retain some curvature. I think the main problem with going further is that post-mid-Muromachi unless it is a top level blade you can't really kantei it precisely.

With this shape and boshi its Nanbokucho, late Muromachi or shinshinto. Nambokucho is probably out. Two other options are both valid without having a more detailed view. Nakago suggests its late Muromachi. Hamon is a bit more shinshinto. It does not seem to have glaring issues, but its not a high level blade either which makes a more detailed attribution difficult.

No one else.