The editorial staff at Playboy.com recently revealed that they have discovered a bunch of dusty old blueprints, plans and photographs in an unfinished basement area of the Playboy Mansion, which unveil a network of underground tunnels that allegedly once linked Hefner’s notorious bachelor’s pad to the homes of “Mr. J. Nicholson,” “Mr. W. Beatty,” “Mr. K. Douglas” and “Mr.…