I can't determine how the mechanism works just looking at the photos on the lock company websites. I think there are some spring return features in the deadbolt itself so it will collapse when you close the door. And then of course it must retract into the door when the knob is turned. The old Bargman lockset functions in this manner.
Maybe there are some Airstream locksmiths out there that have modified a "hardware store" lockset into a custom 3 1/2" backset so it would function on a 65 through 69 Airstream. You can buy a very good lockset for $60. A rare old Bargman L100 can be over a hundred, used.
The 66 to 68 Airstreams are unique with their Coning curve glass windows, phillips window operators, herr vent lifts, cast aluminum door frames, and special Bargman door knobs. These items are getting harder and harder to replace. We gotta develop alternatives.