The only real difference between officer and enlisted is quality. The enlisted have a nickeled numeral, officer's silver plate. The eagle is plain brass for enlisted, or gilt for officers. Also, more often than not the officers version is actually two piece with the eagle being one part and the shield and branch emblem (rifles, sabers, etc) being a second part...however both one and two piece are known to exist.
Also, for the REAL hardcore, there are alot of variations. Regular army ones have rifles that are clearly muskets/trapdoors with the lockplates clean, however there are alot of "militia" plates where they look like a mutant rolling block. I have also seen a version with bolt action krags as the back emblem!!!
Chris Fischer
F-Troop