I have an idea that hasn't been tested yet but I can't wait to give it a try. I'm envisioning one of those extendable/retractable pole sanders (see photos) which consists of a pole and a flat, rectangular head.
I will attempt to permanently attach a piece of rubber to the head of the same width and length.
With this device I should be able to hold the bunk end in a semi-closed position while allowing me to move from side to side to tuck in the canvas. And because the pole allows for adjustable lengths, I should be able to set. Desired length and find the best location on the ground to anchor the opposite end on the ground.
A couple other options come to mind:
1- find a way to attach a female snap to the face of the sander head so that I could snap the device in position on the bunk end male snap until the job of closing the bed is complete.
2- create a permanent flat anchoring block or something that would sit on the ground and provide a more stable anchoring point for the extension pole
Please share your thoughts.