Hello Star City Homer,
I also have a set of 1, 5 and 10 sen "porcelain" coins from Japan, called Tōka (or Toka or Touka depending on spelling convention) Sen. The 1 sen is the common type featured in your photo showing the three 1 sen pieces of different colors, it is closest to the orange at the left of your photo. The 5 and 10 sen pieces have a darker orange color, both with obverse face in the style of the 5 sen drawing in the 2015 Catalog of Japanese Coins and Currency (referred to simply as “JNDA” below) and both having a reverse face in the style of the JNDA 10 sen drawing, i.e., they match your first photo but do not match all four face images in the JNDA.
I have seen excellent posts by you on other forums on these Tōka Sen. Since you seem to have a real fever to learn all you can about these coins, I would like to try to add some more information for you.
I am not a native speaker or reader of Japanese, but have learned just over 1000 of the Kanji and, with the help of Google's often amusing attempts at translation and my wife who is a native speaker and a professional translator, have done considerable work on a few Japanese coin related books. So, in the wish for full disclosure, what I give below has not been reviewed by my wife (I save her for the really tough problems) but represents the best of my amateur ability.
You have mentioned elsewhere a reference by Thomas Alvin Norris III from World Coins Gold Edition, Vol. 10, Whole No. 111, March 1973. I was fortunate to secure a copy at substantially more than its original cover price. As you have noted, Norris in turn has three cited sources that you wished to review. One of these seems to be a report by the Japanese Mint at its 100 year anniversary. I believe I have found this for sale in Japan at
https://www.kosho.or.jp/products/detail.php?product_id=376997157
but, perhaps equally well, what is probably a similar report for the 125th Anniversary of the Japanese Mint is in the public domain and posted at
https://www.mint.go.jp/media/2012/05/ayumi_2.pdf
in Japanese.
Here, as one would expect, we find much of the information is matching Norris. The report states that because of metal being required for the war effort, nominally 15 million pieces in total of all three denominations were manufactured using ceramic production methods during July and August of 1945, but that none of the Tōka Sen were issued, even for one day. So, the JNDA placing all three coins in the Pattern Coin section seems appropriate. As you have noted elsewhere, the JNDA does describe the 1 sen as "Manufactured in Seto, Kyoto" whereas the 5 sen and 10 sen are "Test Castings". And Norris makes the remark about no official issue but one day of circulation for the 1 sen piece. But I conclude that all three are pattern coins and should not be placed side by side in a collection of coins types officially issued for circulation.
As with other sources, the diameter of the 10 sen Tōka is given in the report at 21mm, in disagreement with the JNDA value of 21.9mm. Having said that, I have to say my 10 sen piece is pretty close to the 21.9mm. A photo of all three Tōka Sen is included on page 99, and here one finds the same obverse and reverse faces seen in the JNDA and in World Coin Catalogs of Krause et al.
If you are interested, another Norris reference, Sadenji Nakamura's (中村 佐伝治) Nihon no Koin (日本のコイン) is available for sale in many places such as:
https://books.rakuten.co.jp/rb/137237/
and
https://www.bookoffonline.co.jp/old/0016652202
