Early 50’s bumper. It is case 6804. The case is stainless steel with a coin edge.
I have three of this model, and this is the best of the dials. Each shows various stages of radium burn and patina. I relumed the hands and at some point have to paint the second hand black up to the red pointer. The original second hand was black and matched the minute and hour hands, but it literal broke in half when I touched it.
The current second hand is from one of the other bumpers. It is the same size, but looks as if the black paint chipped off over the years.