I have received a small sprue with the part for the unitary 80mm plate seen on the superstructure front, on the starboard side. This corrects an omission in the original issue of the kit.
The same sprue, apparently designed for the final production StuG.III Ausf.G, also has a multi-part heavy-duty tow bracket for the lower rear hull and a multi-part gun travel lock that mounted on the glacis plate, to hold the StuK40.