Fred, there doesn't seem to be a lot of sense in taking a nice new wire harness that all neat and tidy, and then scabbing a bunch of wires on top of it and running them outside of the new harness to the parklamps. It will be unprotected and look like hell given the level of attention that you've give to the rest of the truck.
Now is the time to send that harness back and order one with the directionals pre-wired. Then it's a piece of cake that COMES WITH DIRECTIONS (and directionals).
Cobbing up the wire harness now is counterproductive to the other work. Cut your losses and start fresh would seem to make the most sense to me. When you get the whole truck back together, you won't want to but if you run those wires on top of your harness, you'll see them every time you open that hood and it will drive you crazy.
You've gone this far to make everything right, why start cutting corners now so close to the end?
