The distance between the "A" and the "M" needs to be the same as the distance between as the "M" and the "E". Sounds simple. The 2000 is the most common. The 1998 is next followed by the rare 1999.
Just remember that as the dies get old and die wear happens, the letters will appear to be moving apart. This will give the look of a WAM. That's why I asked about the distances. The "M" will have the same distance between the "A" and the "E". Just a thought for you