If it's possible to get to the back side................???
Make some corbels from 1X pine, screw the shelves to the corbels first then, screw them in from the back using trim washers. You could add a few more screws to the back edge of the shelf, also.
If you can't get to the back side, I'd make an "L" .... one piece of 1x4 with a 1X6 glued and screwed at a 90 to the edge of the 1X4. You could also fit corbels under the shelf and against the 1X4. Then mount it all to the peg board with plastic drywall anchors. Then use metal 4" "L" brackets on top of the shelf to anchor it to the peg board and help hold it level. Well....I just realized that you'd need holes bigger than the 1/4 ones in the peg board for the anchors. Maybe not such a good idea.
Last edited by Gene Howe; 09-02-2009 at 11:01 AM.