If you are still looking for a cap, do what I did. Go to the Kuryakyn web site and do a search for dealers in your area. It turned out the Harley dealership down the road from me carried Kuryakyn parts and they had the gas cap in stock. I took a ride over during their open house and picked up the cap for $34 plus tax.
Fred
"It's a hundred and six miles to Chicago, we've got a full tank of gas, half a pack of cigarettes, it's dark, and we're wearing sunglasses."