Tiny Japanese Arare tetsu kyusu, maker unknown

I think that this is the smallest usable cast iron Japanese kyusu that I have seen. The length, including spout, is 4.25" and minus the spout, the body of the pot is 3.25" in diameter. It is about 2.25" high minus the handle and lid. It weighs a few tenths of an ounce over 1 lb. The urushi lining shows a lot of use and there is some rusting inside the pot at the top and rust discoloration in the rest of the lining. It has been well used but not abused.

It has a maker's mark that I do not recognize, but pretty sure I have one or two more pieces by this foundry. I have very nice unused cherry bark kyusu in the mail from Japan that is about the same diameter but much taller. This kyusu holds about 4 ounces of water. I am certain that it was made by hand in a single use mold. An initial cleaning with a damp paper towel revived it quite a bit and I will make tea in it to try to seal the interior rust and wipe down the outside with green tea to seal it. I have found that green tea can work wonders on the traditional finish of kyusu. I have read that the tannic acid in the tea converts the rust. My experience is that this process continues to work to darken and seal the rust for some time after the initial application and subsequent applications continue to improve the finish.

There are a lot of tiny Chinese paperweight/novelty teapots on ebay but nothing really usable in this size. It is very well made and the maker's mark is very sharp which indicates a finely molded piece.

This is one that I just took a look at on an on line auction site and the seller offered me a 30% discount, so I picked it up as a research opportunity. It is also only about three hours from my home, so did not enter snail mail limbo as several other additions to my collection did. Probably dates to the 1960s to 1980s.

I have a cast iron horse plaque with a similar mark that I once identified as Iwachu for a now unknown reason. I am no longer certain of this attribution:

https://www.collectorsweekly.com/stories/291328-iwachu-cast-iron-mare-and-foal-plaqu