Door for a battery compartment?
I'm thinking the "fingers" in photo #2 connect the batteries electrically.
And the swivel "locking lever" visible in both photos is what holds the door closed.
It appears to be an access panel of some sort. It is a precision part but not electrical per se as it is all brass/copper (no insulators...).
Maybe for a mantel clock or a small radio? The "fingers" or tabs mentioned by Anduril remind me of some modern desktop computer case "easy removal" side panels. Not saying yours is from a computer. Yours is obviously way older...