Okay, so if I've got this right, there are really the following covers:
Marvel Authentix Sketch Cover - just the plain printed sketch with an empty box.
Marvel Authentix Sketch Cover: Sketch by JRJR and will ALWAYS be a GLOD since Wizard had the sketches done but CGC never witnessed them.
Marvel Authentix Sketch Cover: Signed by Stan Lee - I've no idea if this is a GLOD or SS.
Marvel Authentix Sketch Coer: Sketched by JRJR Round 2 - Still a GLOD or now an SS?
Marvel Authentix Sketch Cover: Signed by Stan Lee, John Romita, and JRJR - No idea if this is GLOD or SS.
Looking at what is available on eBay and he census, it's pretty clear that CGC lost track of what they were calling what. The current two designations they have are probably a mish-mash of the various cover/sketch types.