many watches spent years in warehouses before being sold... If there are some letters incoroporated in the serial number (common with Hamilton and Elgin) your watch was probably made AFTER the last date on the chart.
Both companies went to a different serial number system and the date of manufacture is not determinable by these letter & number serials.
The "New Haven" was dated by looking at the style of the watch. Notice that the watches from the early 1930's still have engraved cases.
By the late 1930's mens watches were more masculine. This was made possible by the advent of square movements.
As you can see from some of these examples, bold and fancy was back in style! Hands got a little wider and came to a sharper point.