I came across this bag last night while pursuing through the Flipboard app on my iPad.
I was really digging this bag because unlike most tool bags that are made completely out of leather, this Roll Bag ($55) from Acorn is handmade out of breathable, water resistant cotton canvas duck with leather straps. Designed for bicycles, I'm sure it could be easily integrated onto a Harley. The bag has three zippered security pockets and a pouch pocket. It measures 8"w x 16"h and is available in a couple different color options.