In addition to the above, perhaps local reinforcing with carbon fibre.

Perhaps epoxy some carbon along/underneath the lip to pick up tensile loads (toe in force).
Like an I-beam the beef is at the ends (flanges). In this case a horizontal beam,
provided the deck is strong enough to act as the web of a beam.

Carbon fibre is approximately 20x - 29x+ times stronger than glass fibre.


Websites for carbon materials:

http://www.acp-composites.com/

http://www.fibreglast.com/