Impressive 8.5x11 sheet, being the last page of a Grateful Dead Productions contract, boldly signed by all 6 members of the Grateful Dead:

Jerry Garcia
Mickey Hart
Bill Kreutzmann
Phil Lesh
Brent Mydland
Bob Weir

The top of the page states:

(iv) the warranties and representations made by GDP in the Agreement are true and accurate

While we do not have specifics as to the contents of the original contract, we can date the piece to 1979-1990 based on Mydland's signature and it is our belief it is closer to circa 1987-1990