Hi Rapala,
Many Type IIs carried a 2cm deck gun. In some photos of Type IIs, a 2cm is mounted on top of a conical mount ahead of the conning tower.
In other photos, Type IIs can be seen with a cylindrical container mounted in this position. I'm guessing that this cylindrical container was watertight. When brought out the 2cm sat on top of this container.
But in some photos it can be seen that no deck gun is present. So not all boats carried a deck gun.
Hope you like the kit.
Cheers,
Dougie