"Air Intake Elbow" bolts shown with their rubber seals. The rubber seals on these bolts look like they are only a single use as they appear to be in an expanded state; the sheath part of the rubber over the bolt shaft shows signs of cracking away from the head part of the rubber. The book says to discard these seals. Not sure if anyone has reused them, and as yet if they are available as a separate part?