tub overflow

I'm hoping someone can help me with the name/type of overflow drain connection in the picture. This is in a drop-in tub and the connection and overflow drain pipe appear to be brass. The house was built in the late 50's and we're missing the overflow plate. The connector has 4 screws and is...

I am trying to find an overflow to fit this situation. One of my guys removed the original overflow during demo and threw it in the dumpster... never to be seen again. I'm used to overflows with either a single or double screw faceplate, but this overflow pipe isn't designed for either. This...