Whats your rarest most hard to find rock n roll autograph in your collection?

Mine would be(as of now) a newspaper article from feb 1969 about the stones rock n roll circus signed by mick,keith,bill,charlie and BRIAN JONES at one of his few visits at olympic studios for the let it bleed sessions,the author of the article had it signed at olympic studios , a few visits it took to finally catch brian aroound march/april....right before he left the stones.

This is one of the last items Brian Jones has signed with the stones in 1969

It was purchased from Tracks UK with letters of prov.  it was expensive but well worth it.