I tapped the fore
and aft sections together.  They seemed
to fit pretty well.  I drilled the ¾"
hole in the forward half with the unibit. 
I then used a round file to open the hole to the 13/16" diameter
hole asked for in the drawings.  I
drilled the holes in the fore and aft halves according to the drawings.
Next I shaped and clecoed the splice plates in place on
the forward half.  I clecoed the aft half
to the splice plates from inside of the pants. 
The fore and aft sections seem to fit together very well.  I must admit I had to do quite a bit of
marking and sanding to get them to fit together this well.