Strange Iron Shin-Kanei Tsuho

Georg from Finland writes: "I had lucky to find this interesting iron coin, size: 21.9-22.1 mm.
I am not find this coin from Ogawa Yoshinori/1969 Catalog,but there is many similar elements with copper Akita-sen/y.1738,Catalog # 124."
Georg is correct. At a glance, there are similarities with Akita coin called Chuji-Kosui. However, 寶 on Chuji is written much higher than this coin pictured. There are also many minute differences. Granted, this coin has rusts, and rusts do sometimes distort the characters. But they do not rewrite them. Can anyone ID this variety?