until today, all of the air conditioners that Airstream has used, were "top" of the line at that period of time.
The only problem with the older units is the lack of adequate BTU output.
Today, 15,000 BTU units are available.
Back then from 1964
to the 1969 models 10,000 BTU was all that could be had.
Technology, in time, rewards most all of us with improvements and better designs.
Look at most any car today from even 5 or 6 years ago.