As I said on the home page, this site is a work in progress. I am still researching, and sometimes the best reference is another person instead of a book on a shelf. In the hopes that someone out there has an answer or two, here are a few of the questions that continue to baffle me. If you have any insights, just go to the Contact Me tab up top and send me a message.
One appears to be redrawn in a book I have, and I'm trying to find the original illustration. The caption given in the book is「佐州仕立金銀図」所収の金貨図 (新潟県立佐渡高等学校同窓会蔵 舟崎文庫文書). I don't have any further information about the original work it came from, but it shows the coins themselves, not the mine or the mint.
According to one Japanese book from 1999 and one Japanese dealer, we don't know what the significance of the number of marks is. I'm not yet convinced and am currently tracking down new sources in hopes they'll shed some light on things.
I've scoured my sources for information about the Gaku ichibu, and while I've learned a lot and answered most of my questions, I haven't found anything at all to suggest a mintage number. Is there any record?
The Rectangle Coins