Both players and collectors alike consider a guitar’s nut width and neck profile to be very important. Gibson changed the standard nut width many times from the 1930s to the 1960s. The information below is a generalized break down of what you can expect from a standard Gibson guitar from each time period.
1930s: Usually 1 3/4″ (44.5 mm) wide nut. Many V neck profiles although round is common as well. Hawaiian style guitars: 1 7/8″
1940s: Usually 1 3/4″ until 1947. Wartime necks with no truss rod are often 1 7/8″ and very full. Nut width decreases to 1 11/16 in 1947. 1947-1950 neck profiles are a bit more full than the 50s but not as hefty as a wartime guitar.
1950s: 1 11/16″ (42.9 mm). Neck profile is a medium to full heft round C shape. Neck profile decreases in heft for 1959 only slightly. Electric guitar players consider the 1959 nut width and profile the most desirable.
1960s: 1 11/16″ until 1965. Nut width decreases to 1 9/16″ (39.7 mm) in ’65 and continues until the end of the decade. Neck profile decreases to a thin profile in mid 1960. Gradually increases (on average) until 1965. 1965-onward profile is a standard c shape.
Gibson necks were shaped by hand all through this time period so there are many exceptions to the rule. One exception is that the Epiphone nut width decreased to 1 9/16″ two years before the Gibson brand instruments even though they were manufactured on the same line. Go figure!