I'm sorry that happened to you and like others, I think you could file in small claims court, or possibly even get a judgment, etc.
However, what happened isn't civil, but is a crime - no matter what the local police say. She basically stole your money. In Arkansas we call the lawyer who represents the state against criminals the prosecutor, but in other states they are called State's Attorney", or District Attorney. You need to make an appointment to see that attorney or his or her deputy in your area. I think he or she will agree a crime was committed and file charges once you relate that you bought the trailer and then she sold it AGAIN before you could pick it up and refuses to refund the money.
Your state's attorney general or whatever they call that office in Texas may be of help, too. What happened wasn't civil. The police just don't want to open a case on it. It was criminal. The services of the official attorney with the job of prosecuting crimes are free to citizens. You don't need to hire an attorney. You already have one paid by taxpayers.
The first and most important thing to tell the prosecutor is that you paid for the trailer and mad arrangements to pick it up and she then sold it before you could pick it up. Did you pay by check? If so, get copies of the check and any written correspondence or documentation and take it with you to see the prosecuting attorney. In most states $1600 is considered grand larceny, although I don't know the amounts in Texas. She could be arrested and jailed. She would then get a trial and upon a verdict of guilty would have to pay you back your money.
As for the trailer, any old trailer is going to be a challenge and a lot of work, but they are worth it. You may have even ended up with a better trailer. Make it yours and you'll fall in love with it as you work on it and get to know it.
Good luck, and as others said, the forums will have information on just about every issue or problem you have and if you can't find the thread, just ask. People here are always ready to help a new Airstream owner.
Best wishes to you!