11. Here is how to make the gun turrets rotate.
Start from glueing together parts 45 and 45a (also 46 and 46a for the wing turrets). Make a small hole in  part 45a (pin size). Cut out part 48, insert a pin cut to 4-6 mm lenght, drive the pin through the hole in part 45a and secure it with the piece of paper from below part 45a.
Apply a small amount of glue only on the paper circle, from below the whole assembly. With some luck, part 48 will freely rotate against barbete 45. Only now attach turret 47 to part 48, they should rotate together. Finish the turrets by installing gun barrels and small guns on the roof platform.