We love this old brass ashtray, it's made like a real working port hole! It's not marked with a makers mark that we could see, possibly English brass? The shape is spun, not simply cast.
It's beautifully detailed, and we're guessing 1970s or earlier from the workmanship and the tarnish. It's about 4 1/2" in diameter overall, with a rubber ring at the base to keep it from sliding around if you use it on a boat.