the main question is. Based on your writeup you are trying to use the brake filament as the turn and the brake? (assuming you have a two wire two filament bulb one for parking one for braking/turn)

If you do that 5 wire setup is not going to work well. its designed for a separate turn signal light bulb on the rear

if you search NOS Signal Stat 700 with 5 wires and wiring diagrams you will see some nice writeups.
This person has a 53 they did that type of wiring on and has a good diagram.
The tech tip also explains this in detail as well.