I just bought a vintage cabinet and some of the speaker cones are looking a little brittle near the edges/surround. There appears to be some water spots on the cones so I'm assuming these became wet and then as they dried out, they started to become brittle. What product would be recommended to apply to the outer edge of the cone in order to prevent splitting/tearing of the surround area? Some kind of RTV sealent/glue? I can see that the factory applied a nice glossy layer of glue/sealent ect to the surround and the outer most edge of the cones but the speakers that have the water damage appear to no longer have the glossy edge. I'm afraid if I play the speaker at any sort of volume I'll shred the cones! The cab is a nice old Acoustic 404 model with six 12" speakers. The first pic is the speaker without any of the glossy edgeing. The second pic still has some gloss to it. I hope this helps!