LOS ANGELESFriends say Dennis Sierpinski, who worked as Chris Penn's body double until the actor's untimely death last month, has been 'seriously packing on the pounds.' 'Dennis has always been a stocky guy, but formerly, he was required to keep his weight down to Chris Penn levels to keep working,' said friend Rachel Rosen. 'Now there's nothing holding him backI can't believe this is the same guy who doubled for Chris Penn in Starsky & Hutch.' Friend and former River Phoenix body double Allan Shedd has urged Sierpinski to seek look-alike bereavement counseling. 