Overall it looks great. I really like the finsh and the setting. Very nice.
As to the 152mm ammo. It is a two part, semi-fixed ammo. It has a brass case w/propellant inside and the projectile which come separately in the box. There are a couple types of propellants. One is a fixed propellant molded into the case. The other has propellant charge bags like the US uses.

Mini Art does a really nice 152mm ammo set.

The 152mm round is quite a bit larger than a 122mm round though.