Vintage Magic Mirror Door Detective Door Peep Hole 2 Way Mirror Home Security

Description

I'm guessing 1930's - 40's on this two-way mirror door peep hole device. It was called the Magic Mirror Door Detective. Made in New York. The company was Magic Mirror Associates-Pat. Pend. The round portion is 3.5" in diameter. About 4.25" tall. Sliding doors allow residents to view who is at the door. Sliding door can be locked in the open position.  Appears to be all brass. I believe the rectangular opening at the top was for an apartment number or name. I'd safely say it's never been used. See last photo for minor finish flaw