Hi Pam, the gasket needs to make a good seal or the volumes will be very low. You can use leather lace available on eBay or a craft store like Michael’s. Once you install the lace you need to coat it with a thin film of silicone if not it can create light mold. As for the grey felt, I make and sell the replacement felt pieces as well as silicone washer replacements, if they are cracked you should replace them or at least the ones cracked. If you are interested send me a message on the Monsters of melodica Facebook page and I can give more info.