Great picture-video and information, respectively, Dave and Rick, thanks! The whistle soundings are definitely cool and don't sound banshee-like, more of a throaty multi-chimer. In the one color photo of the dirty I1, you can certainly the resemblance to a Hippo 
As I mentioned earlier, the Premier Hippo has a simulated-circular boiler underneath the mid-section that is very well done, and in studying the photos Dave provided above it's very accurate to the real thing.
