19th (?) century Meiji (?) tetsubin

This tetsubin is 6" in diameter x 4.25" high minus spout, lid and handle and weighs 3 lbs 6 ounces, about a one liter kettle. It is unmarked which, with the prominent attachment points for the handle, makes me suspect that it is an older kettle, perhaps late 19th century, late Meiji period. I do not often see a tetsubin that is not marked.

It is rather simply made and decorated, with a rolled steel handle. Possibly the work of a small, local foundry that made fairly simple wares for people who did not have the resources to buy more elaborately decorated kettles or brew large quantities of tea. From the estate of a deceased collector. It was very inexpensive and I do not very often see kettles this old at reasonable prices. Basically, never.

Inset into the second image on the left is a close up of a temple or shrine feature and in the inset on the right a close up of mountain and tree features from the opposite side, but also what I first thought was a pretty significant flaw in the casting, a noticeable vertical groove. I am now on the fence about whether it is a flaw or a design feature. Not really first class work, though, and more support for manufacture by a local foundry that is intent on making serviceable tools, not perfect ones.

It has been well used and cared for with minimal exterior rust, except for the bottom, though the inside is rusty and coated with mineral deposits. It is very dusty. I am undecided about how to treat it. My first instinct was to brush down the outside with a stiff nylon bristle brush to loosen and remove dust and debris and then boil green tea inside it to seal the interior rust and then wipe down the outside with green tea to blacken and seal any exterior rust. I would have no qualms about using this process on a newer kettle, but not sure that it is the right thing to do with this kettle based on its potential age. It appears to be in stable condition, so I will let it rest for awhile until I decide on the best approach for maintaining it.

Calling a mystery until I can arrive at reasonable estimate for dating and possible origin. Not doubt that it is Japanese.