The reason I did a double-take when I saw it was its uncanny - and as we will see, surprisingly accurate - resemblance to an EMD SDP35. For a cheap kids' toy, it's a most irregular choice of subject. I say this chiefly because the SDP35 was not widely produced; intended to replace older passenger locomotives and still run as a freight unit if necessary, it only sold 35 units during 1964 and '65. Meanwhile, the standard SD35 sold 360 units in a similar timeframe. (The successive SDP40 and SDP45 models only sold 20 and 18 each, respectively; the 34 'SDP45s' sold to Erie Lackawanna were without steam generators, in order to equip a larger fuel tank than the standard SD45.) Union Pacific ordered ten; finding them inadequate for passenger train service, they used them for freight until their retirement and kept their fleet of EMD E8 passenger locomotives in use until all passenger services were assumed by Amtrak in 1971.
I mention UP's locomotives because this toy is painted reminiscent of UP's color scheme. While logos, lettering and numbering are all a work of fiction, the gray top portion and yellow body are correct, even to the red stripe that separates them (it should, however, be a single stripe, not the paired one on the toy). And 'Power Pacific'? They got it three-quarters right, actually! I count 'Power' for partial credit since Union Pacific was once the buyer of many imposingly massive and powerful locomotives, both steam and diesel.
But better yet is how closely this toy actually matches the real SDP35. Starting with the wheels, it has the early Flexicoil 'C' trucks, and heavy braking option (with one cylinder for each axle on each side - correct for the UP units); while the nose and cab aren't perfect, they are identifiably EMD designs; the traction motor blower duct and hood bulge, as well as the bulge in the steam generator compartment at rear are all present on the fireman's side; and the air intakes, dynamic brake blister at the top center of the hood, radiator shutters and vents for the steam generator at the top rear are all correct as well. The only real glaring error I can see is the radiator fans. The prototype had two larger fans with one smaller fan between them; this has three large fans like the SD40 was built with. The two dynamic brake fans are correct.
Of course, only a complete nerd like me would even notice, but I do find it very interesting that such an obscure prototype was picked for such a relatively unimportant-seeming kid's toy. I know I've seen more than a few based on EMD's much more widely produced F-unit locomotives, which makes more sense - with over 7000 of all F-unit models built, they were a much more common sight on the American railroad scene well into the 1980's. The SDP35 is all but extinct by comparison.