Help needed in determining Pirates signed baseball

WFFL

A lady called about a Pittsburgh Pirates autographed baseball she has had in her possession since (?) 1968, 1969, 1970. She read the following signatures on the Spaulding BB: Willie Stargell, Al Oliver, Luke Walker, Jerry May, Richie Hebner, Fred Patek, Manny Sanguillen, Bill Virdon, Doc Ellis, Gene Alley, Gary Kolb, Bob Veale, Steve Blass, Bruce Dal Canton, Larry Shepherd, and Bill Mazeroski. No Clemente (sigh!). Does anyone here have any idea of a value for this? Thanks in advance.

Gregg