Hi Greg,
While the Red Devil and Ebbing were certainly not my favorite locos, they did represent an interesting attempt to prolong the use of steam and have some historical significance as a result. The Red Devil started out with a whole host of alterations designed to improve efficiency and increase horsepower, but most turned out to be maintenance headaches and were gradually removed. By the end, about all that was left were the twin Lempor exhausts, larger superheater elements and the altered cylinder steam passages that were designed to reduce back pressure.
From a railfan perspective, the loco produced almost no smoke, needing cold weather to show a white steam plume, plus the exhaust blast had the typical sound of all Porta modified locos, a sort of pocketa, pocketa sound, lacking the satisfying exhaust blast that is typical of normal steamers. If you have ever paced the 611 across Ohio, with the gear hooked up almost to center, it sounded a bit like that. It was also really slippery. All that added horsepower could only be used at speed, so it slipped a lot getting started.
The red shade changed over time and at one time the solid red was relieved by a white stripe along the running boards and along the tender sides. Also the shape of the elephant ears changed over time as well.
Michael Allen