Use the code wheel to spell out the event.
      Example
      Date:   March 1965
      Rule:   Multiply by 2
      Event:   24-10-15-21-8-27-15-16-10
      Solution:   Look on Code Wheel
      48-20-30-42-16-54-30-32-20
      S   T   A   M   P   *   A   C   T
1.   December 1773         Rule: Divide by 2
      Event:   4 - 88 - 96 - 40 - 30 - 86 - 58 - 98 - 10 - 60 - 116 - 32 - 2 - 36 - 40 - 50

2.   June 1775         Rule: Subtract 8
      Event:   39 - 58 - 22 - 48 - 42 - 26 - 66 - 45 - 17 - 20 - 49

3.   July 1776         Rule: Multiply By 2
      Event:   2 - 17 - 16 - 6 - 15 - 9 - 15 - 10 - 19 - 22 - 7 - 29 - 22 - 3 - 29 - 19 - 7 - 2 -
                    17 - 18 - 17 - 7 - 2 - 17 - 7 - 16 - 17

4.   July 1789         Rule: Multiply By 2, Subtract 1
      Event:   22 - 8 - 24 - 25 - 19 - 12 - 3 - 10 - 25 - 15 - 8 - 24 - 17 - 5 - 22 - 1 - 22 - 2 - 3

5.   April 1775         Rule: Multiply By 2, Add 3
      Event:   10 - 28 - 8 - 17 - 3 - 20 - 2 - 23 - 6 - 20 - 13 - 13 - 3 - 20 - 20 - 28 - 9 -
                    2 - 9 - 22 - 28 - 23 - 1 - 15