I have a 79 Blizzard 5500 and the plastic seat base is cracked in the middle where it starts to cover the tank. In other words, when you lift up on the seat near the steering stem there is a lot of give. I am planning on recovering the seat and want the base repaired "right". Any ideas on how to repair? I'm thinking some kind of plastic repair, but I'm not familiar with what's available and what to use. It has to be very strong. What kind of plastic was used on these seats? Thanks.