Hello chucklubly, welcome to Air Forums. Using the classified section of these forums is a good way to find the Airstream you want.
A diligent seller will provide responses to inquiries about the advertized trailer. It may be there is a pending negotiations and the seller isn't ready to respond to further inquiries. However, as a courtesy, they should. Trailer negotiations are private and you should have given the seller an e-mail address or a phone number to reach you privately.
There are lots of Airstreams for sale all the time. They are in demand now meaning prices are trending upward and they sell quickly. But given some patience, you should be able to find what you want.
There are Airstreams listed on e-bay and craigslist (not my favorite). I purchased my 66 Trade Wind on e-bay.
Pick another one and see if the response isn't better.