Found in my father's vast assortment of "stuff" last year.
No markings at all aside from a flower motif stamped into the leather case.
There are two small sight-glass type things which fold out, one with green glass and the other appears to be black and completely opaque.
On the opposite side there is a small button but pressing it doesn't appear to have any effect. I haven't even figured out how to open the thing.
It appears to be good quality, like all things manufactured in ye olden days, but not top quality.
I have no idea what to do with it.