My 88 Dolphin bathroom faucet is leaking and the culprit is the gasket in the hose from the tank that connects to the faucet. I cannot find this gasket anywhere. It is gray and like a washer but has an extended area that is thinner and fits into the hose. The RV places have all said that I should change out to compression hoses, but I'd rather just replace the gasket. Does anyone know where I can find this part? Thank you!