This seems like an odd phrase. I am not sure that "vintage" means classic in this sense any more than it would mean the year or place in which wine was produced, the wine itself, or even grapes (the latter are all nouns). Moreover, if "vintage" described the word "inspired," it would be an adverb. The word "vintage" cannot be used as an adverb and since it is not adjective, it cannot mean "classic." Therefore, the only option is that it is a noun.
Since it is a noun, one would have to have to know the context in which the phrase is used in order to determine its precise meaning.
