That's a great item - I too have one that is framed. It's from my first visit to WDW way back in 1972. Back then, they didnt' give out park maps like they do now, you had to buy a map if you wanted one.
There were, I believe, two updated maps of the MK sold after this one. I have the one from c. 1977 as well as a map of EPCOT Center from when it first opened that is in the same style as this map.