You don’t give a lot of pictures so difficult to say. But don’t worry too much about the rubber doesn’t look flat anymore. As long as it’s relatively flat so that you can glue it easily, it’s fine. It’s just rubber. When the rubber goes out of the box, it looks amazing. Whatever you do with it it’ll look worse. But you don’t buy the rubber to look at it 🤣 You only know if you don the job right AFTER you glue it on and have a hit unfortunately. Also if it’s a Chinese rubber, give it a couple of days if you don’t hit very hard. It needs some heavy hitting to take effect.