1Buckshot, I'm sure a bunch of the guys here can relate!
kmitch-
Short version:
Rack Grade- Fair condition, all original
Field Grade- Fair to Good, all original
Service Grade- Good to Very Good, all original parts may have new wood
Service Grade Special- Very Good to Excellent, all original parts will have new wood
Correct Grade- Very Good to Excellent, all original
Collector Grade- Excellent, all original
CMP Special- Excellent, original receiver, new barrel, may have other new parts and new CMP wood
Additional things people look for are manufacturer, makers of barrels, accessories(grenade launcher mounts) and C/D(sniper) types.
My SGS is all original parts, likely rebarreled by military armourers in the late 50's early 60's with an LMR barrel(which I'm told is a good thing) with new CMP wood. Both the muzzle and throat gauged 1+ which puts it in the excellent range. I went down hoping to find an SGS "shooter". The fact I walked out with the only SGS they had and in that condition was awesome!