Hello,
wonderful model !
Control means "Steuerung", in german. It is the right translation, however it has a lot to do with "steering".
The conning tower or "sail" as it is called today on US subs, is the "Turm" in german. However the room where all informations get to, from where the boat is managed, and from which orders are given, would be the "Zentrale" in german, for the central control room. "Kontrollraum" or "Steuerungskontrolle" would also be possible in german.
Conning or con tower is an abbreviated word of Control, i am pretty sure.
Greetings,
Catfish
P.S: b.t.w. Mr. Bauer already invented a U-boat, the "Brandtaucher", in 1850. But its "Turm" was a rather small affair ..
http://de.wikipedia.org/wiki/Wilhelm_Bauer_(Ingenieur)