Main Harness Wiring Question 1967 GT500

[cboss70]

When I got my late 67 the previous owner took parts off for a refresh, never labeled anything, and then let it sit for decades before coming to me. I'm trying to make sense of a few wires and my old wiring diagram isn't helping me (I'm sure its me not the diagram!).  I am hoping someone can tell me what these purplish wires are for, the single thicker pink one and the red/yellow with red/green that go into a single plug are for. 

Additionally, the back of my cluster has a black and red wire for the tach. I have a tach harness but have no idea where and how the two connect.

If anyone has pictures or can fill in the gaps I'd appreciate it.  Thanks.

[cboss70]

More Details:
If it helps , things that are already plugged in/connected are:
headlamp switch
radio speaker
heater switch and box
the main gauge cluster minus the tach
Ignition switch
steering column
brake light switch identified
washer pump and high beam switch
heater blower motor
flashers
rear harness
engine compartment headlight harness
wiper motor
underdash curtesy lights and door ajar switches

NOT Hooked back up because I can't tell where to do it:
Tach
under dash gauge pod
all the wires in the above pictures

Not hooked up because I just haven't done it yet;
Ammeter wires from engine compartment

[Coralsnake]

Do you have a wire with a cloth jacket, possibly pink and a male bullet on the end?

[Coralsnake]

Purple wires are for brake warning