If the plow is a 16" can you put 12" or 14" landslide shares on and convert it. I don't know if the moldboards are the same and how that all works. Thanks
If the beams are set on 16" centers you can't change the width of cut without changing the beam centers (which is impractical in most instances). The only antique plow that comes to mind designed to alter the width of cut halfway easily would be a John Deere #44.