What is it?

[Tin Can]

This is a special and odd lens. Looks like new, but Zipcode 4 is wrong as Chicago had 2 digit zip codes in the 1920's

It says 210mm but needs about 16" to gain infinity focus and worse it can focus very close about 1" to an object from 4"

IMG-2568 by TIN CAN COLLEGE, on Flickr

IMG-2569 by TIN CAN COLLEGE, on Flickr

IMG-2570 by TIN CAN COLLEGE, on Flickr

[Gary Beasley]

Has the appearance of a copy lens and would have to wonder if there are missing lens elements if the infinity focus is so far off from what is marked on the lens.