A NMB reader messaged me about what happened with this sword.
As I mentioned in the thread, the NTHK-NPO papered it to Ko-Mihara. I thought it was Kamakura, and Darcy had a nice photographic demonstration of the identity of shape with a Sukezane (now gone on this very old thread). The thread also had a lot of debate about muneyaki and other interesting topics, so I decided to go ahead and revive it, even though it got a little chippy at times.
When the sword was being fitted for a habaki and shirasaya, Mishina San reached out to me about the nakago. The habaki maker suggested that the nakago be filed and restored because of the active rust, and Mishina San supported that. I approved.
When it went to NBTHK, it papered to Sue Bizen. I don't recall whether a specific maker or sub-school was mentioned. I was disappointed because the tang looked much more like that of a much younger sword, and I will never know, but thought that change in image might have influenced the shinsa team.
I have moved cross country this month, and my papers are yet to be unpacked after the move. I will dig them up when the unpacking gets to them and see if they said more than Sue Bizen.
Cheers, Bob