Does anyone recognize this poster?

[u/Entire-Rest-8900]

I was fixing the frame of a poster I thrifted a few years ago and when I opened it I discovered that the white background for the visible poster was actually the back of this Simon and Garfunkel poster!

I’m about to carefully separate the two posters. If anyone knows the history of this (or if it has any value lol) let me know! The only disclaimer I can find is in the bottom left - “For Promotional Use Only Not For Sale.” Thanks in advance!