Hi Anthony... MAN would I love to go on this trip with you. Wish I had a usable Airstream, I've got a broadcast quality cam too. Nuts. My thoughts and prayers are with you for 'the bomb' of a documentary trip. When do y'all start?
Here are 2 links for folks in Texas that may be able to help you with an Airstream:
www.airstreams.net ...speak with Erica
www.classycamping.com ...speak with Debby (JoAnn is on vacation)
I've JUST emailed Debby at Classy Camping. She has a 1967 Airstream. I know it's one year off the magic number but worth a look!
God Bless & PLEASE keep us posted!