16th century Sekisyuu-Gin

Hello I believe I might have a very rare type of Gin-Ban coin called a Sekisyuu-Gin, 

It was allegedly minted in the 16th century Iwami Ginza Silver Mine.

Below is my suppose  example  of a Sekiyuu-Gin [Top] along with a confirmed example of one [Bottom]

Reverse side

And below is the certified example as well as what appears to be a sketch detailing the history of the Sekiyuu-Gin.

 Unfortunate it is  the image is not detailed enough to be able to use Google translate to confirm what is written about it.

The source of the image had a rough translation of the description left by it's owner detailing what it is 

"Description SEKISYUUGIN is a silver coin made with silver which Is produced in Iwami-silver-mine in the late 16th century.Coin KOBAN of SEKISYUUGIN is rare in Japan.I do not know whether it was actually distributed.The paulownia box is attached. ■Size of a SEKISYUUGIN KOBAN.4.7 cm(1.10") in width.8cm(1.73") in length. Weight34g/ 1.20oz. KOBAN coin has a sculpture of the Pure silver.It's carved by a Japanese kanji.Age Unknown. Material Silver"

So I was wanting to ask if somebody here was familiar with these types of Gin-Ban coins & could tell me more about it or if mine is one of the many 18th century restrikes or Fantasy Gin-Bans?

What you have is a reproduction of a silver bar/coin according to THIS site (I couldn't find anything about the alleged orginal as of yet).

“In 1969, Iwami Ginzan Silver Mine was designated as a national historic site.
To commemorate this event, a replica of the koban was produced based on the design of the time when it was in use.
The crest of the Tokugawa family, which ruled the country at the time, is also engraved on the koban.”

I greatly appreciate your help you have solved what has been a months long search,

Prior to learning the name of this piece it had been a good mystery as to what exactly it was or when it was made,

Thank you.