Please help identify Japanese Mon subtypes

I have been gifted some beautiful old coins from Japan. I believe that these three coins are all of this type: N#121454

I can see they are different from each other, but I can't match what I can see to the descriptions given on the coin page for each line item. Please could I get some help from an expert who can tell me which variant each of these are? (Or, naturally, if any of them are not coins but copies or charms.)

First coin:

Diameter: ~ 23mm

Thickness: unknown - in holder
Weight: unknown - in holder

Second coin:

Diameter: 23.1 mm

Thickness: 0.8 mm

Weight: 2.13 g

Third coin:

Diameter: 23.4 mm

Thickness: 1.5 mm

Weight: 4.14 g

None of these coins are magnetic and all have a blank reverse, as seen here from coin 2:

Is it normal for there to be such a big variation in thickness and weight among these coins? Are they supposed to be 23 mm in diameter or 25 mm as the Numista page says? I really don't know a lot about these and any help would be most appreciated.

These coins were made for hundreds of years by hundreds of, sometimes tiny mints, so yes there are considerable differences in size and (sadly often only tiny) ones in calligraphy.

Personally I would use David Hartill's catalog if you want to find out if it a major sub-type.

You can also ask Sak he is the main referee for these kind of mon coins.

Your coins all look genuine to me and are all of the  new kan tpe copper issues.

I would like to expand on the reply by Idolenz.

The book by David Hartill is “Early Japanese Coins”.  You find it pretty easily, for example, at Amazon.  Some coin dealer sites will also carry the book.

My personal preference for copper cash of Japan is to team this with “History and Guide to the Copper Cash Coinage of Japan” by Robert M. Jones.  This book is a little harder to find, I know it only as listed at ebay by the author.  As I write this you find it at

https://www.ebay.com/itm/255665752945?hash=item3b86ddcb71:g:rxEAAOSwyDJiw1v~

As the site address may change with time, by searching for this text string you may find it again:

"Japanese Coins Book Tsuho Mon Pre-Meiji Cash Catalog"

The two references have of course some overlap, but also have differences in the coins they cover.  The images in Hartill seem to come from the Japanese JNDA catalogs (for sure this is the case for the Tempo Tsuho) and those of Jones are traced to Japanese coin books by one or more past collectors with the name Ogawa.  All of these sources are in Japanese and are even more expansive, but the language barrier can be difficult.

Thank to both of you for replying! This is some great information.

Hi,

1 - 加島銭斜冠 KASHIMA-SEN SHAKAN

2 - 四ツ宝銭永勁永広寛 YOTSUHŌ-SEN KEIEI KŌKAN

3 - 秋田銭中字降水 AKITA-SEN CHŪJI KŌSUI (low arms)

All of these are just my opinion can can be incorrect. Recheck is recommended.