Ahh yes I completely forgot to mention about this. The disc tab came already mounted to the rear left hand drop out, which is why I’m going with a matching disk fork. And yes you’re right, there are bosses for v brakes/cantilever brakes on the rear stay.
Has the rear disc tab been added?
Aren't most Kleins rim brake only? Also I'm assuming the 'V' in the name refers to V-brakes.