Your flickr link is messed up,when you enter flickr you have to go to the right to see the close up of the pollock autograph.I see the rip in the magazine.Get a expert to certify it.

I started collecting in 1967 when my dad gave me a Mickey Mantle autograph.I have several sports and art related autographs.I only buy deceased autographs now.

You have a very rare autograph.Perhaps one-of-a-kind.I am a Pollock fan and collector.You need to show this to the art world.That is his autograph,I am very familar with this.Amazing find.