Steve, Welcome to the forum and it's great to have another forum member here in the valley. Janet was right on about the rail on the top of your trailer. Other brands of awnings were made to fit, but as far as I know, now only ZipDee makes one for the rounded body Airstreams. The good news is that ZipDee makes the best awning, the bad news is that they are not cheap. I just installed one yesterday, and you can see my progress on this thread:
http://www.airforums.com/forum...ect-20240.html