I am in the middle of a project and am using cosworth brakes to stop the beast, I've been looking for braided hoses and found that they come as a set of 6. Normally as I understood it - there is only a need for 4. Is there an additional flexi hose fitted between the rear swinging arm and the caliper?

 

yes, on the rear there is a flexible pipe on each side from the body to the arm, this then runs along the arm in solid pipe to near the caliper, then from this to the caliper again in flexible.