The one thing that makes me think is second pic from the bottom the patina seems to be different in the same shape as the hamon and sorta stops right where the clay mixture for a retemper might have been. Maybe in an effort to make it go into the patina and make it fool an armchair expert like me? And the yasurime seem to be a little obscured there too. On the other side though it looks a little like someone polished into the nakago once on that side a little. Maybe to see where the hamon stops?
Would it be a terrible idea to have that area only and like a millimeter on the other side polished to see what the hamon actually does there?(not a suggestion a question)
When considering something retempered i like to keep in mind that most of the time a retemper was simply done to restore a ruined blade to usefulness. The higher quality the retemper(ie harder to tell like this) the better you can probably hope at least that it was done in the past by a master who simply wanted to save themselves some work, or rather save the work of someone else.
I was pretty sure the minamoto sukekuni i posted was retempered when I bought it but i just loved the hamon and figured for the price i guess i was getting two master smiths for one blade, but i have now convinced myself its an original hamon, and these guys say be wary of the signature 🤣😑🤣. Still happy with it! In the end its worth what someone would pay for it. Im sure one of these guys wants its as bad as i sorta do.
I REALLY still believe that other one was a retemper (a promising wazkizashi recent thread) and not the exception to the rule the other guy pointed out to me. In the end youre gonna have to shinsa it and hes gonna have to shinsa that one. Im gonna have to shinsa the minamoto. Hopefully we all dont know nothin and you got a 10k + in your hand. Everyone pray your wrong for him.