Hello again NMB members,
I posted this original information request back in Sept. 2016. I just wanted to follow up with anyone who may be interested as to what I have discovered.
Shortly after I had purchased the sword, my research indicated it as possibly Kanbun era 1661-1673 Sukekuni. I eventually dismissed this probability because the mei was slightly off from those I had located for comparison online...
Thus, I made a plea for help with NMB members in order to prevent myself going completely insane over the matter. Stephen (Oyabun) kindly provided me with information also indicating the Kanbun era Sukekuni of which I much appreciated, but promptly rejected as those among us that really have no business studying nihonto often do.
I thought due to the slight differences in mei, and the well preserved appearance of the nakago, this could not possibly be Kanbun era.
I've since come to the realization that nakago can be well preserved with file marks fairly intact, as for the mei, I couldn't begin to speculate what is 100% proof of sword smith signature, but am sure there are normally going to be slight differences, particularly in older blades.
Therefore, due the above observation, as well as sugata and additional factors, I will return to Stephen's (Oyabun) original suggestion of the sword smith being that of the Kanbun 1661 Sukekuni .
Again, NMB site always appreciated..
Dave M