One might be a Wide AM and the other a Close AM Have you ever heard of WAM's and CAM's? http://lincolncentresource.com/Featured/1992DcloseAM.html
Yes and I do know about those and I know the G makes the differance. Except the AM does have a seperation between them.
A worn or polished die would change the appearance/size of the FG. You would know easily which AM it is. Even spacing between the A M E is a wide AM. Touching AM wide ME is close. The FG (actually Strong FG) only applies on the 88.