The 9cm c73 was the first gun to be sized to 8,8cm. The same gun, adapted by the Imperial German Navy, was termed L/30 8.8 cm. It was designed as an anti Torpedoboat gun, and served in that capacity on capital ships for decades. However, naval studies concluded that the hitting power of the piece was inadequate, and a new designed weapon system appeared shortly before the outbreak of the Great War. This was the Krupp M1913 8,8cm SK L/45. (SK standing for Schnellade-Kanone, fast loading gun.) On the photos below you will note that the gun has a vertical sliding breech block, a common feature with fixed ammunition German naval ordnance. You can also clearly see the weapons are crewed by Naval personnel.

It was an excellent weapon, and had replaced the puny L/30 pieces on capital ships by the war’s outbreak as an anti-aircraft weapon. By the late fall of 1914 numbers of these guns were being emplaced along key Flanders coastal positions and the North Sea. By October 1918 there numbers made them a highly effective piece of naval ordnance to dissuade allied air interdiction at key locations (Zeebrugge, Brugge,etc).

Later in WW1 this gun (and its ammunition) was used as a basis when a special 8.8cm AA Gun was developed for the German Army, a gun that after the war was developed into the famous WW2 "88".

There is no kit available, so you will have to scratch build it.