37mm deck gun?
Impossible; the 37mm rapid-fire deck gun was an Austro-Hungarian and bulgarian weapon, not german. the german ships used the 8mm machine gun.
but if you want I will search some images of these weapons.
One thing; if you want add a K.u.K. campaign, you have to make the UB-2 class (these boats were the most successful subs of the KuK navy); I hope the you will make more subs than those of your list.
Sorry if I seem presumptuous
PS: good work
