Remember with the seat back pocket, there is a second zipper that expands the size of the pocket. On the package it should say it's a .58 qt box. (If you still need a pic, it will have to wait for daylight, and maybe the rain to stop
On rope: The tool kit size, I use a spare piece of spectra line (same as the rudder line) Super strong and thin, with a loop on the end to "leash" it.
Both the Lunch size and one of the Gear size, have a leash of light (50# work load) colored line with a loop at the end. (Lowes $3-$4 for 50') They are in the hull most of the time and usually only come out when mostly stopped (lunch or a gear change).
The one Gear box has a red line, and holds my safety gear (EPIRB, miror, extra batteries for the Marine and GMRS radios, etc) and is stored far back on my right side, with a second Gear box in front of it. It's "leash" reaches to the center hatch and has it's own small SS carabiner. I always know where it is because of where it's loaded and it's red leash.
(I carry and practice with emergency gear so I don't have an emergency!)
The only minor problem I find with the Lock-N-Lock's is that the cover is seperate (not attached) but I only have one box out at a time in the water and have not had a problem holding the box. I do usually leash the cover while I'm eating lunch on the water if in wind or waves (tied to a buoy).
On a couple of odd Lock-N-Locks, (like the one on the aka support) I have drilled a hole and added a SS hardware to attach the top to the base and still be waterproof.