Cloud City Drones stocks a wide range of DJI parts. Never have purchased anything from them. IIRC, replacement motors for the Neo were ~$29/each. Might as well purchase another Neo. Guessing like the motors all their OEM replacement parts are expensive. Not even sure if legit company.
Have you consider an aftermarket foam type of gasket. Most seem to require velcro v. the tabs on the original. Initially was concerned with the rubber being uncomfortable when conditions get warm. Wasn't as bad as I thought it would be. Was considering the NewBeeDrone Max Comfort. Have ordered products from NewBeeDrone. Competitive pricing, good service. California based company.