the spring wrap isn't for esthetics it spring keeps the tube from kinking when they bend round. its hard to remove the spring after so from a labor stand point they leave it on.
basically they have the flat tube, install the spring, install the fittings, double flair the ends of the tube. then bend it round. you can't get the spring off easy so they leave it and it matches how ford did it anyway.
the fluid amounts going front and back are different depending on options, if you have drum brakes, or power drum, or front disc manual or power front disc brakes. there is a proportioning valve that biases the pressure sent to the back of the car.
the front reserve in the master feeds the rear brakes, and the rear feeds the front brakes. the larger reserve is for the fronts.
the front brakes do not go through the prop valve and get full pressure when you press the brake pedal, the rear line goes through the prop valve on the drivers apron, and the pressure is restricted to the back drums. there is like a 60/40 bias in pressure might be more, because you want the front brakes to come on first before the rear engages, and also disc brakes require high pressure compared to drum brake wheel cylinders. if the rear wheel cylinders got full brake pressure for a disc the seals might pop.
now the prop valve also has a brake pressure sensor if one side of the system springs a leak a shuffle inside will get pushed to the low pressure side and trip the dashboard light that you have a problem with the brake system.
also the reason that the lines coming out of the master are rounded and do not go straight into the prop valve is due to body flex, vibration and car accidents. a straight brake line is more efficient but will break when the body flexs. the round lines absorb movement and vibration and in a car accident won't snap so you at least maintain braking power as long as possible.
