The very first thing to realize when attributing 1883/2 shield nickels is that they all were made in 1883.  Therefore, if there are characteristics of an 1883 shield nickel that differ from other years that would certainly be a valuable diagnostic tool in eliminating candidate coins from an overdate attribution.

Fortunately, there is an important attribute of 1883 shield nickels that lets us do just that.

In 1883, the U.S. Mint switched to a different style of numbers for the date, called a different logotype.  The numbers for all 1883 shield nickels are spread more widely than in any other year.

Here are pictures of an 1882 and an 1883 shield nickel side by side.
 

Note that the spacing of the digits is much wider for the 1883.

Here are cutouts of just the date portion of the two coins above, at exactly the same magnification.

With the dates stacked one on top of the other, the difference is even more apparent.  I like to look for the gap between the 1 and the first 8, and the gap between the second 8 and the 3.