Good spot. I am not aware that this has ever been discussed here before.
I’m not convinced that it’s a Super Chief, but on the other hand I can’t tell you what it is. We (think we) know that everything in the Tomica World range except for the Amtrak and its red and blue F-unit variants was derived from the Plarail 1994-2003 range, but there is nothing there that matches this.
You can see that it comprises a locomotive and two similar or identical trailing cars, i.e. the rear car is not an unpowered copy of the locomotive. In this respect it resembles the F-unit 3-cars. You can also see that the trailing cars have a body that drops down between the wheels (like for example the Super-View Odoriko), the F-units do not have this.
