Maker: (Nihon Photo)
Model: Adams 57A (Montgomery Ward)
Cell type: Selenium
Measure type: Reflecting / Averaging
There are about 1,000 Japanese meters that are all very, very similar to this one; they have minor cosmetic tweaks and variations, but I believe they all come from the same company (Nihon Photo), which sold it under all kinds of different house names. "Adams" was the house brand for Montgomery Ward, similar to the way Sears used the "Tower" name.
One fun thing about this, however: they had the decency to brand the actual maker's name on the back: Kuwano Electrical Instrument. They appear to be still in business: a maker of electrical meters. They seem to have the typical corporate myopia about their own history. You can click on the link for "history" and then on the photo of the meters, you get a corporate timeline. (This version goes through Google translator into English.) If you look at it, it appears that they began business in 1904, and then absolutely nothing happened until 1950.