Do you have the transition dates, by any chance? I don't know what your book(s) say on the matter so I thought I'd ask.
Well that's funny because many a decal sheet show various E-4s in use with JG27 in 1941.
I've got page 26 (I think) of "Bf109 in Action" that shows a 1941 E4 trop with sandgelb and oliv mottling and belonging to 1/JG27 (according to the caption). I've got a decal sheet scan of an E-7 on the same decal sheet that claims this one (the one I skinned) was an E-4, and both E4 and E7 are listed as "Libya 1941". I've also got a separate high-res decal sheet scan for an E-4 with the later-era solid sandgelb halfway down the sides over solid light blue, and it's listed as being an E-4/N of Group Commander II/JG27, Libya, Summer 1941, flown by Colonel Gustav Rodel.
On page 45 of "Bf109 in action part 1" it mentions something I missed. It says that in April 41 JG27 went to Africa. It had E-4/Trops. 1./JG27 wnet into action on the 19th and three days later it was brought up to full three staffel strength, when 3/JG27 arrived. It says that not until June 1st did the fourth staffel arrive, bringing with it 6 welcome 109E7 reinforcements.
Too much info out there... hard to know which is correct. I'm reasonably confident one can gather as much info as possible and make their mind up based on the info at hand. I'm open to info you've got (always), but so far I'm leaning toward the skin being an E-4.
