I just replaced both of the plastic skylight covers on our '08. They age in the sun, and then start cracking. You are lucky you found it setting still, rather than have it depart on the road. I got ours at Out Of Doors Mart, but should be available thru any Airstream dealer. I searched on line for a non-Airstream part, but could not find the same size. Good luck with your replacement.
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