I tried to model the NYCTA's Broadway Junction before 1940s? There is complex trackwork! Are there any track maps of the area? The latest "Tracks of NYC Subway" book isn't clear.
These maps (scanned from an ERA Bulletin) cover the 1930s-era layout, after the Canarsie Line connection via the upper level platform at Broadway Jct had been completed, but before the Fulton St Elevated was abandoned: https://tramway-null.blogspot.com/2013/12/source-linder-b.html