Play the level where you liberate the fire station.
When you go to the railroad to blow the bridge, when you first
get down there you will see a derailed boxcar with the IO logo
and "47 UNITED".
Play the level where you seize the police station. From where
you start, go to the streets. On the one corner is a red, white,
and blue diner with the name of "OG's". On top is a
billboard for a men's suit designer, featuring 47.