Well, I don't know about a 1966
Airstream but this is what I did on my 1998 Excella. Call up Airstream at (937) 596-6111 and ask for parts. Give them your VIN number. Airstream then will give you the Tri/Mark key code for your door and all the other codes for all the other locks. Then call Tri/Mark parts at 800-431-8616. Give them the key code Airsteam told you. Then Tri/Mark will mail you a key already cut! They can even overnight it to you for extra dinero. As for the rest the locks ( water, battery, storage), call your friendly Airstream dealer and talk to the parts dept. Give them the codes and they will sell you keys or keys with locks.
I hope this helps