I've got the same one at my place. It came from a Tyco trainset about 20 years ago. Did you get the caboose along with it? The caboose was a slanted cupola with the same silver and red colors.
As far as the model, it resembles a smorgasboard of B-axled U-boats. Apparently, Tyco couldn't decide decide on what type of loco to model, so they made up their own. Only the front axle is powered. I haven't run this baby in years, and the last time I did it was the electric-razor-doing-laps-on-the-track routine. To be honest, I haven't taken it apart for maintenance either, so that will probably help. Mine had two speeds: on and off. However, I think that was due to the cheapo Tyco transformer that came with the set.
The paint is interesting. It resembles the ATSF passenger War-bonnet, but Tyco put the Union Pacific shield on the front. I know a railrod ran a "Silver Streak," but I can't recall who or when. I keep meaning to buy some HO snaptrack to get this baby running again, but I can never find a complete oval, or even enough parts in one place to make one without shelling out 50-60 bucks.
Tough little loco, BTW. Mine took the 500' drop so often that the engineer earned some frequent flyer miles. Never stopped running, but was real sensitive to gaps in the track. I'll have to look at mine when I get home to see if the rear wheels pickup electrons or are just there for the ride. Glad to see another one of these out there.
BDC