I did some stress analysis.  The stress is derived from Alum 7075-T6.  Bolt hole plate is 0.5", holes are 12mm.  Peg is 6.5" and overall length is 7".  I used a 600lbf spread evenly over the peg.  This is a 2" wide peg.  There is also a 0.5" radius on the bottom side of the peg above the bolt holes.

This is a very quick sketch.  This should give everyone an idea of where the high stress areas are.