Joe, there is a modeler at the Bf-109 lair that also did this aircraft:

http://109lair.hobbyvista.com/models...mdm/e4_mdm.htm

He also lists it as an E-7. As far as I know, the E-7 was basically an E-4/N (the /N designating the use of a DB601N engine), but with provision for a drop-tank or bomb. The E-4/B on the otherhand is an E-4 (DB601-Aa engine) fitted with a bombrack. I am not sure if there are any external differences between aircraft fitted with the DB601-Aa and the DB601N. It is therefore quite difficult to distinguish between an E-4/B and an E-7 from a picture like that. I know the E-7 could carry a droptank - but I am not sure if the E-4/B was also able to do so instead of the bomb. The one in the picture cannot be an E-4 as it obviously does have a bombrack, but it could very well be an E-4/B. The late spinner suggests an E-7, but it is difficult to say for sure. Looks like some further research will be required...