Interesting lot. This collection was put together each year as the cards came out. The stickers from 1976 and 1977 are indistiguishable but since these sets were put together as they came out it's likely safe to assume that one set really is 1976 and one is really 1977. Not every possible variation is included, but many are and there's at least one of every sticker from both sets. Not an easy task to replicate!