One day it struck me that this could be the solution to my wrapping problems. It was indeed much simpler than the fancy ideas I had been planning involving plastic pockets and elastic. The shelves were perfect for holding essentials like pens, tape, tags and ribbon all that they needed was some card inserting as a base to stop things falling through the gaps in the bars. The I added a canvas tote on the hooks at the bottom to hold all my wrapping paper and hung it in this space behind my desk.
The bag is working great for holding flat sheets of wrapping paper but not so great for rolls so I think I need to make 2 bags in place of the canvas one. One a small rectangular bag for holding folded sheets of wrapping paper and one a long thin one for holding rolls. I'll post more pictures if and when I actually get around to it.