Josh,
I think you'll have a hard time finding these. I couldn't source them when I did up my bike 2 years ago. I ended up finding some suitably sized rubber at an auto jumble and cut into length. I think the rubber must have been off of some HT lead or similar for a classic car. You might find some rubber hose the right size. I've also used rubber hose to take up the distance between the tank and frame, as I've a 52 bike with later rubber mounted tank.
John