I've added the following to the Pulk v4.0 post but here it is again.
I think I'm going to use a shock cord lashing system to secure the load into my pulk. It took nearly 35 feet of shock cord to "lace up" my pulk and the way I secured the ends was to use a super sized cord lock. Now the cord locks that are available for purchase are way too small! The 3/32" shock cord would never fit so I decided to make my own. I cut a one inch piece of pvc pipe to 4 inches. I then sanded down a wooden dowel to just fit in side the pipe. A 3/8 inch hole was drilled in through both. A very stiff 2" spring was sent down the pipe from the end that didn't have the dowel sticking out. To cap off the end I used a 1/2inch piece of pvc pipe. It just happens to fit very snug inside the 1 inch pipe. This plug was driven in with a mallet until the desired tension was reached. Now I am able to pull the shock cord tight and secure it with the cord lock.