This is an interesting little lens. Physically about 4.5 to 5 inches long about 2" at the front with an aperture scale from 4 - 16. It does not have a thread on the rear for mounting but at about 140mm at infinity it covers 5x4 with slight movements -- slight.

It is a Petzval configuration as far as I can determine. I have had the rear group apart. It has the very definite Petzval swirley bokeh.

There are no engravings on the barrel or inside the barrel that I can see.

So -- any ideas what it may be?