Did any navy develop three-axis stabilization for fire control before or during the Second World War?
Short answerYes, the Dutch, and their systems influenced the Royal Navy's early Hazemeyer stabilized mountings.
NotesThe Dutch navy pursued three-axis stabilization. British engineers dismantled and examined Dutch equipment after it became available to them. The Royal Navy's early Hazemeyer stabilized mountings drew on that work. This was wartime technology transfer from a smaller navy into British anti-aircraft fire-control development.