I've had this for a few years now, and decided maybe someone else would like to make it also. Not complicated at all, but works for us while out riding and not wanting to hold everything in pockets or lose it in the bigger compartment spaces. Others have addressed this issue I'm sure - this is just "my way". I used a piece of 1/4" pegboard I had laying around, but many things would work I'm sure. I've included JPG sketches (2) that you can use to make 1 complete template for each half, but I caution all...….make sure you check your printout for correct overall sizes as I note on the sketches.
You can scale JPG up or down if needed in Excel, but I couldn't find ANY program I have that would print the JPGs at PERFECT SIZE the first time. So much for 100% sized copies of things from printers


FYI - Part of my reason for making the shelf this way is because I can put it in or take it out easily in 2 pieces, without fighting the compartment sidewalls, etc.
Oh BTW, the underside (which is usually UP in ours) is covered with household rubber shelf lining matl. so things don't move around much. Also, the forward lip sits on top of the "dinner plate" Velcro area BRP installed, and the rear edge sits just inside the lid closing ridge.

Any questions, please just let me know. Complete shelf.jpgSpyder RTL deck shelf part2.jpgLeft side.jpgRt side half.jpgSpyder RTL deck shelf part1.jpg