Info On Cast Japanese Needed

I have David Hartill's "Early Japanese Coins" book. At first I was going to confirm your research and tell you I could be of no more help!

But there is a chart where the alloys for different mints are listed. There is a note that the coins from Osaka contain enough iron (4-5%) to be magnetic although they are still mostly copper-alloy. So I think that is an acceptable deviation to be magnetic but still not listed as an iron coin.

However the mintmark listed for Osaka has two horizontal lines at the top of the gen character. I only see one in your image. Maybe that's due to the photo or corrosion or other factors but thought I'd point it out.

Four Osaka coins are listed, with the best match being Hartill #4.197 (Ogawa #274, JNDA #132.59). The defining feature is the upward slope of the top horizontal line of the Ho character (at 9 o'clock position) which I believe I see on your image. The rarity is listed as Very Common.

As for the other coin, I agree with your assessment of Sendai mintmark. Hartill lists only 5, all iron. So no help there.


I am no expert but was happy to try using my new reference for you. If anyone else has any ideas, I'd love to know,

-wheatiefan

The Sendai coin could be a brass mother coin that has slipped into circulation.