At first I thought it was the gate portion of a gate valve as on the first pic the two things on the side looked like guides. But after seeing there are holes I have no clue. Cool find.
It is a nozzle of some sort it seems by interanl design? the threads on the one inlet are NPT and the from the inside you can see it is machined to flow something. Pretty sure it is an old pressure washer nozzle but can't put a maker to it. Even used google lens.
Yes I see the similarity of a gate for a valve to some folks. but not thinking it is. It is designed to flow something it seems, a lot of unnecessary design if a gate for a valve but who knows?.