Greetings and welcome to the Forums!
Airstream hasn't been known for its consistency with model name usage since about
1968. Since
1968 the meaning of a particular model name had a tendency to change from year to year. Prior to
1968, the model name (Safari, Overlander, Ambassador, etc.) referred to the length of the trailer while Land Yacht applied to the standard equipped model and International referred to a upgrade option that featured a variety of components that did change from year to year. About the only way to determine just what equipment was included in a particular year's trailer of a given model is through the sales literature as even when the model names were more consistent in the 1950s and 1960s, the standard (Land Yacht) equipment level varied to a degree and the components included in the International package varied from year to year.
Good luck with your search!
Kevin