glass and brass case of a 400-day (anniversary) clock, probably from the 1950s–1970s.

The clues are:

Curved front glass panel.

Four glass sides with etched corner decoration.

Brass-colored metal frame and dome top.

Rotating lock on the front.

Four leveling feet underneath.

Mounting holes in the base for a torsion pendulum movement.

The actual clock movement, dial, pendulum, and suspension spring are missing.