Thank you for contacting Mearto with your appraisal inquiry. Based on the photographs and description provided, the subject of this appraisal is a Spalding NBA basketball autographed by Wilt Chamberlain (1936-1999). According to the current owner, the piece was acquired via inheritance. The piece features a certificate of authenticity from a defunct authenticator (Champion Sports Collectables, Inc.), and the certificate of authenticity is of the variety that could be easily duplicated via photocopy, so unfortunately the signature cannot be considered authenticated.

A PSA-certified similar ball sold at Heritage Auctions in December 2019 for $630.

The signature on the ball that is the subject of this appraisal does appear to be consistent with other known Chamberlain signatures. In consideration of the factors noted, a Fair Market Value (pre-auction estimate) of this piece conditional upon signature authentication by a reputable third party such as PSA would be estimated at $600 to $700.