There is a good discussion of
inflation adjustment at Duke University's website. This is the extremely simplified version.
Pay particular attention to paragraph 3 which begins with "Use of the "correct" price index is important if you are interested in knowing the exact magnitudes of trends in real terms..."
Online calculators are OK for general guesstimates of inflation, but are not suitable for something as esoteric as Airstream values. There are specific deflators for certain things, but they are more slanted to broad categories, such as food or housing. This, in a way, is like asking how much a vintage Airstream is worth. Difficult.
More detailed information can be found at the
Bureau of Economic Analysis (BEA, part of the US Department of Commerce—search for deflator). If you find this interesting, you should work where I do.