FMC,
Sorry I don't what else to call you. The most noticeable would be the engine nacelles the G.V's are more like power egg and those of the G.IV are much larger structure. The forward section of the fuselage is differently shaped on the G.IV than the G.V which has a bulge on the port (left) side at the pilots station. The propeller guards are differently shaded on early G.IV's. The one other difference I can think of off the the top of my head is the wings early IV's were much straighter in platform than the G.V or late G.IV's which had a greater sweepback.
Perhaps my conversion using the Aurora Gotha will make this clearer for you.
Gotha G.IV Starboard side nacelle.
G.IV with lesser degree of sweepback.
G.IV Port side front section of the fuselage. Note the new window and the lack of the bulge at the cockpit.
Gotha G.V Port side of the fuselage and the power egg engine nacelles.
G.V Note the greater degree of sweepback to the wings.
G.V Starboard side fuselage.
I hope these are helpful to you my friend.
Highest Regards,
Gregory Jouette
