Hi BUKER,
it´s not a Mod, it´s just a change in the config files of the Uboat.
It´s just eyecandy and not playable.
I changed this because the late-war IX D2 didn´t have a 10,5cm deck gun but had a 37mm Flak gun (U-873, U-875).
If You are interested I´ll send You the necessary files.
многие привет от Германии
Kurfürst