From 2008, a George Steinbrenner autographed baseball offered for sale in the Yankees' Team Store in Yankee Stadium...
(Photo taken June 21, 2008. © Gary Dunaier. Link to upload on Flickr.com: here.)
And from 2009, an image of a George Steinbrenner signed baseball included as part of the "Ball Wall" in the Yankees Museum in the present (fake) Yankee Stadium...
(Photo taken August 11, 2009. © Gary Dunaier. Link to upload on Flickr.com: here.)
For obvious reasons both signatures are presumed by me to be genuine.