Up for Murder poster - Vintage movie public domain poster

Poster for the 1931 film Up for Murder.
There are no copyright marks. At bottom left is Country of origin USA. At bottom right is Morgan Litho Co., Cleveland, O. USA 36549.
United States Copyright Office page 2 "Visually Perceptible Copies The notice for visually perceptible copies should contain all three elements described below. They should appear together or in close proximity on the copies.
1 The symbol © (letter C in a circle); the word “Copyright”; or the abbreviation “Copr.”
2 The year of first publication. If the work is a derivative work or a compilation incorporating previously published material, the year date of first publication of the derivative work or compilation is sufficient. Examples of derivative works are translations or dramatizations; an example of a compilation is an anthology. The year may be omitted when a pictorial, graphic, or sculptural work, with accompanying textual matter, if any, is reproduced in or on greeting cards, postcards, stationery, jewelry, dolls, toys, or useful articles.
3 The name of the copyright owner, an abbreviation by which the name can be recognized, or a generally known alternative designation of owner.1 Example © 2007 Jane Doe."