Kronos

A bit late to the party but Late Kamakura Aoe would be my guess, specifically Tsunetsugu. The jigane looks reminiscent of some Bizen especially with the utsuri; I guess the close proximity with Bitchu would explain that.

Agreed Michael, the few that are papered would of been my first interest and that always begs the question of if someone has a collection with only a few papered (recently at that) then why are the rest not?

I'm planning on going if only to look. The estimates are low but if it's found it's way onto NMB then I imagine there won't be any bargains to be had. Was kinda hoping it'd fly under the radar as the catalogue isn't on any of the online auctioneers and I've had a few good deals from here before.

A dealer was my first thought, this reminds me of a story Darcy mentioned a while ago about a gimei Masamune he bought at Christies. Everyone thought it was gimei iirc which made them hesitant to bid on something that turned out to be a Sadamune or another high level smith. Although I think it is probably Shoshin I get the feeling the downside is at most ~$30k and there's terrific upside. I don't shop at anywhere near this level so take it with a grain of salt...

This is not as much a gamble as it seems. I'd bet shoshin and there's a small part of the kissaki that looks like you could get a good look at the hada/hamon in hand. Notice the internet bidders stopped at $2k so the two (or more) who pushed it up to $55k were most likely in the room and would of been able to take a much better look. Worst case scenario (other than having a hagire or being only shintetsu left which is the risk you take with anything out of polish) it looks easily Kamakura so even if gimei only the better smiths/schools were making tanto like this for the bakufu making it a juyo candidate. Then the upside I think Paul eloquently eluded to. It wouldn't surprise me if the new owner was a member here.

Edit I may of been horribly wrong.. didn't see the oshigata which shows midare utsuri that isn't visible in photo's. Looked like a cutdown shinshinto to me...

That's a relief. I couldn't imagine them passing that. The chinese fakes are getting much better but still a long way to go on the basics like patina and shape before even considering jihada etc

Koshi-no-hiraita is associated with the oei bizen school. Iirc it was copied by sue bizen such as sukesada and probably some edo smiths. On the sho-shin website there's a good example by morimitsu I believe.

I mailed in a hirazukuri ko-wakizasi that passed as den osafune yasumitsu which I'm very pleased with. After polish the hada in particular looked like later muromachi although it was dated oei (half the signature was too faded) although everything else fitted oei bizen. No idea on points yet. I'll see if i can find some photo's.

It looks like 11th Gen of the Edo branch to me.

Much more complicated I'm afraid as their naga-mei (full signature) would be something like noshu-seki ju kanemitsu but they also signed often with a shorter niji mei (two character given name) for a variety of reasons. So it could probably be any of the 20-30 mino smiths or possibly one from a different province.

Maybe Bishu Ju Kanemoto? Can't really see the first two kanji.

Yes, almost certainly a Tachi but they were still common up to Oei and while they were most common around 72-75cm from what I've seen from this era a good percentage with 78-80cm+. This papered Toshimtsu from 1399 was the first example I found but certainly over 31" before suriage. Also p162 and p384 of Markus' Koto Kantei Zenshu from a brief scroll shows a couple more though most seem to of been shortened. Ko-Mihara lasted up until the start of muromachi from what I've read so anything 1300-1400ish could be considered not having seen the NTHK papers whether they specify a date. I'm just going off other schools really as to sugata putting it later. Although I guess for ko-mihara it could just as easily be late Kamakura. Kantei from photo's is not easy unless it's a bit obvious as there's so much info gained in hand and especially suguha like this is one of the hardest imho. Did Mishina-Sensei give an opinion? As I'd trust him more than almost anyone else.

In the absence of more info I'm going to have to agree with the NTHK and say ko-mihara dating to the end of nambokucho/oei. There's many similarities to oei bizen smiths/kozori working in an osafune- mono suguha of late kamakura like kagemitsu. However there's simply too much nagare/masame.