Bunshudo cast iron mare and foal plaque

This Iwachu cast iron horse plaque is 8" (20 cm) in diameter and is 1.75" (4.44 cm) deep. The tabs at the top each protrude 1" from the plaque. It weighs 2 lbs and 4 ounces (1 kg). It has the maker's, some additional text (date?) and "JAPAN" stamped or molded or etched on the back. It came in its original box with some documentation. It also came with a wooden stand that I forgot to photograph. It has never been opened and is still sealed in its original packaging.

I have a small Iwachu kyusu/nabeshiki set in my collection which has the same text on the box:

https://www.collectorsweekly.com/stories/293225-iwachu-persimmon-cast-iron-kyusu

Here is an interesting video about Iwachu cast iron ware, anyway:

https://www.youtube.com/watch?v=o6AuxztRkYM

(I continue to ramble on about Iwachu) The quality on this piece is a bit below what I typically see on Iwachu cast iron, or else it has suffered a bit from neglect, or both. There are some casting errors on back and maybe on front or else it was allowed to rust and pit an then cleaned up. I made it bit worse by rubbing on it with a damp cloth to see if it would clean up. Guessing it would not have passed quality control if the issue on the front was due to casting errors, so leaning toward surface disruption and pitting from rust. The ear of the mother horse has popped through the box on more than one occasion and is a bit shiny as a result but not damaged, just polished.

The more I dig into Iwachu's products and history, the more variation in products I find. Best known in the West for teapots my guess is they play a much larger role in Japan. Or once did. Another horse themed item and I am guessing it celebrates the year of the horse, though I have not yet tried to decipher the information that came with it. No idea when this was made, but it feels older, like maybe 1950s or 1960s. The box is pretty brittle.

Update: I was able to translate everything but the label on the top of the box, but still not sure of the foundry that made this:

Nambu horse bookmark
The anecdote about this horse goes back a long time. It is so famous in myths, legends, and history that it has been devalued as a symbol.In recent years, Kazutoyo Yamauchi's horse, a famous horse of the Genji clan, was used as an ink for living. Many of the famous horses seen in the history of equestrianism during the Tokugawa period, such as Mata, were all produced by the Nanbu domain. Nanto Koma is famous all over the country, and wall plaques and ornaments are made using the special Nambu iron kettle technique in the shape of a running horse. It has received wide acclaim. If you hang it in the entrance hall or in the living room, it will be a great decoration. It will be a sign of good luck and will bring you good fortune.

This concubine is the same hobby
Southern Ironware

Wall hanging
Horse Ertou
Our southern ironware rock casting-