That is not a part anyone sells, it is integral to the hood. You could, if you had an industrial sewing machine (mind you will be sewing through three layers of fabric and one piece of plastic), remove the fabric hood, pick out the stiching and replace with whatever you think suitable. Easier would be to source a good second hand fabric on fleabay. Some come in at reasonable prices. There is no magic to replacing the hood, I have done it and there is a guide in Gen 2 section or a better one I posted on NAM. It's for the Gen 2 but identical process for Gen 1.
Cooper 2009, R57.