Here’s the 1970 poster which is displayed in the Delta Blues Museum. Although it’s a dream poster for blues lovers, it has two big problems: It’s widely attributed to 1964, when in fact most experts say it’s 1970, some of them after extensive research. And with blues artists, it’s always a matter of “the earlier the better,” with things being commonly saved by the 1970s.
The other problem is that this poster was heavily copied / bootlegged from an early time, perhaps even as early as the 70s. And the reproductions were spot-on perfect, using the exact same colors, cardboard stock and dimensions. So most collectors just steer away from it because it’s so difficult to tell the few originals from the thousands of knock-off’s. (These are not to be confused with the 21st century Globe Classics reprints, which are clearly marked.)