I suppose you could use a straight edge and math, but it seemed to me that this way is easier and more accurate. Back up. First I want to show Bruce my nut:

You can see that it is pre grooved.

So that gives me the lateral location of the strings as they enter the fret board. I'll file into them to set the height of each string when I get into set up at the end of this.
But for now, I need it mounted where it will be sitting when it's done.
Here's its home :
The nut is radiused to 10". My board is 12". So I'll compensate with a very expensive nut slotting file later.

I started getting all clever and trying to put pieces of wood up the edges and clamping it from the side to make sure it was flush on both sides and didn't move around.... You can see the clamp on the desk... But then I realized... Just use tape, dip shit.
Now the bridge :
The two u shaped parts at the top edge are where the bridge will pivot against the posts. The location of those posts is crucial. Vital even.
The bridge has holes through it where the strings go around to the back of the guitar.

They come up over the saddles.

The saddles are the grey metal blocks that have that slot and the 2 adjustment screws {one in each half. ) There are 6. One for each string