Pretty confident on the authenticity but appreciate confirmation or concerns from the group.  

FDC dated February 2, 1990, signed by:

• William Rehnquist (as Chief Justice)
• Clarence Thomas (appointed 10/23/91)
• Harry Blackmun
• Sandra Day O'Connor
• Stephen Breyer (appointed 8/3/94)
• John Paul Stevens
• Byron White
• David Souter (appointed 10/9/90)

Signatures were likely added over time but all justices served after FDC postmark.  LMK your thoughts.  Thank you.