Rivkin

Yes the style of hamon is typical shinto. Weird size/sugata, suspect it had a major crack and was shortened considerably. There are couple of things which I really good - entire hamon is composed from well distinguishable nie particles and there are "gaps" within it where nie is less dense. These are difficult things. Unfortunately this smith's ambition resulted also in multiple ware, so its not the top class work by far. Also - better smiths in almost every school practiced this kind of style. Can be Kyoto, Osaka etc. etc. Maybe 1650-1660 or about. Seeing boshi might help.

Overall view is usually important, but it looks like late Muromachi Bizen work.

Love the piece! I would think this is some generation around 1640 when Bungo produced quite a few blades in Hizen style.

Attributed to sue hosho and it does look Muromachi but the quality is Impressive.

It would paper, but if its post Nambokucho, its a Problem.

Muromachi pieces, probably 70% kantei can't be done with certainty. Too many similarities, any new submission will yield a new name. Green papers, Kanzan and Nishu sayagaki - got to see if its something that can or can't be definitively kanteied. If it says Yamato Tegai or Naminohira, chances are good it will stand the test of time. If it says Shizu Kaneuji its probably Muromachi Mino or Sue Soshu.

... And now I feel really stupid

You need to show the nakago and to the lesser extent the boshi. It may be signed; most people would reserve their opinions since they are likely to look stupid when the signature is uncovered. So far however there appears to be a pronounced koshi-zori combined with a periodic relatively wide and uniform hamon which is formed by groups of two. This hints towards late Muromachi Bizen from 1520-1550 or so, possibly Sukesada.

The nakago is long, patina is not too deep, yasurime is clear and well spaced. Even though its suriage it hints towards shinshinto. Consistent with wide mihaba, long, uniformly curved blade. Wide gunome chouji with nie "foam" remind me of Chounsai Tsunatoshi and his school.

Hamon seems to be in gunome and there is some evidence (how crack propagates etc.) there is masame hada in shinogi ji, so its likely to be Mino type, but taking nakago into account I would say Echizen seki, end of Muromachi. Frankly its a big stretch for a blade in this condition, but I see nothing so far to dispel this attribution.

Can we see the boshi? Its outline, hamon line is very important.

The pictures are not great, but a good guess would be late Muromachi, uchi-gatana. If there will be a good photo showing activity on the blade one can venture further in the attribution. Or possibly date it earlier.

The blade is very straight with some taper - Kambun shinto comes to mind.

There is some potential, but the photographs are all bad. Crazy angles, light from the ceiling - it will not work. Boshi, activity, sugata has to be clearly shown. Light source needs to be from a side.

Fail to see the issue here. 95% chance such rust can be polished out. The price is within range for a signed Nanbokucho blade in such condition. Now whether one believes this piece or not its a different matter and I do have some reservations.

My take on the issue is a bit unconventional. The problem is that even if you can't see the crystals it can still be nie, just a very large or very densely packed martensite area. Its not uncommon for Edo period works. To me the comparison has to be between how the blade appears with glancing light (kissaki towards the light source, observing from the nakago) and side light (observing from the top, light on a side). If both are comparable its nie. If glancing light reveals much more, its nioi.

Kajikawa is a school and family. 90% of their work is from roughly 1820-1880 though earlier pieces are known. I feel like the katana stand is later than this, late Meiji or Taishi. I think they did not work after that but might be wrong.

That looks like a typical Taisho period or about work. Lacquer is datable, first and foremost because the methods of processing gold (or yellow colored alternatives) changed, the wood changed somewhat and in some cases the composition is a bit different. There is a percentage of items which are not datable beyond "Edo period".

That's post war. Yes, pre-1900 are a bit rare and expensive.

All this "stuff" by default is Meiji or early Showa. Showa and Heisei lacquer cracks more aggressively than anything old.

I think surprisingly the only way to go is by lacquer (shape of gold particles, color etc.). Otherwise even a multi-piece stand is apparently a very conservative form.

Frankly at this level the only question shinsa is going to answer is what's its default bucket for lower grade shinto works - Bungo, Echizen Seki etc. etc.

Its an interesting blade, however hamon with very fine and pronounced bluish ayasugi looks shinshinto. There is overall "freshness" in work uncommon in koto. Still most likely going to be a major smith, but its not that old as they claim. That's the reason why no papers.

Its hard for me to comment since I don't see any strong positives here. With late Mihara you want very pretty jigane, and there are many examples of such. Here its bleak, non-repeatative, disappearing in certain areas. Its still ok tanto, nothing horribly wrong with it, but its basically 700$ without koshirae and 1000$ in some old beatup mounts. That's what a collector would consider paying for it. Koshirae here is basically the cheapest you can assemble from around the shop parts and the only thing that is not awful is tsuba. I think one of the problems you are looking for a package with koshirae and those tend to be put together in Japan for beginners and often not really strong collectibles.

If its Tensho the damage is high already, multiple wares, subtantial thinning from nakago to the blade, on suriage at that etc. etc. If its Nanbokucho Soshu circa 1360, if you get tired Hasebe with ware its still ok price wise after polish. I suspect its Tensho, but based on such photographs its still a very slim evidence.