Thanks for posting the pic of SHIGEKUNI Brian. From the even rust, some people may be tempted to think the sword is older than SHOWA Jidai, but please be assured, it is definitely not earlier. I should also say that my earlier description of the tang as KENGYO should really be called IRIYAMA GATA.
I have been doing some study of the later NANKI SHIGEKUNI smiths, Shinshinto era, and this sword's tang, yasuri and mei characteristics match quite accurately. The blade does match some aspects of later NANKI line hada, boshi and hamon but in shape is typical of SHOWA era Gendai swords made for reliable hand to hand fighting.
Thank you all for your interst and help...now I wait for the incredibly knowledgeable DR. T (who is he?)...
Regards,
Geo.