Endless pictures available online. Just do a Google search for “Olympian Hiawatha.”
(You can’t simply copy and post copyrighted images from the web here, so asking for prototype images of a train that hasn’t been around for more than 50 years is a no-no.)
The MTH 70-foot cars are way too short. K-Line made an aluminum 21-inch set (84 feet) that’s highly prized. 3rd Rail recently released a GGD set as well.
Here’s my K-Line Skytop Lounge and Kato N-scale set.