How do I identify?

I came across a unique find while dumpster diving recently, There were 2 cars and an engine wrapped up in old rags in an old crate someone had tossed…

The engine measures 7 1/2" long. It is marked, “5405.” The bottom is marked, “Rivarossi, Made in Italy.”

The, what appears to be a coal car, measures 6 1/2" long. It is also marked with “Rivarossi, Made in Italy.”
The reason I question it being a coal car is, on the backend of the car in small print it reads:
25,000 GALLONS
Dupont 10-28-41

The 3rd car is obviously a newer model that does not fit in.
Anyone have any idea what I have?
I have a few pics here:

http://www.drfxt.com/2_car_side_view.jpg
http://www.drfxt.com/back_view.jpg
http://www.drfxt.com/coal_car_top_view.jpg
http://www.drfxt.com/engine_side_view.jpg

It does make me want to build a set again. I had a “kick a**” set when I was a kid.
Made my own sets. It was fun then and I have an inkling it may be just as fun now.

Thanks for any input.

It would appear you have an NYC 4-6-4 Hudson engine and a tender from either a UP 4-8-4 or 4-8-84. In real life they do not belong together but they look pretty good together in the photo.

As ndbprr said you have a tender. This tender carries coal and water for the steam locomotive. 25000 gallons is the water capacity.
Enjoy
Paul