This guitar is probably among the first twenty Martins made in 1939 after the change in nut width on 14-fret models from 1 3/4″ to 1 11/16″, so yes it is 1 11/16.
It has all original finish. Original tuners. Original maple bridge plate. It has multiple repaired cracks on top and sides (no cracks on back). Extensive play wear. New, but perfect, historically correct reproduction Ebony bridge.