Dredging For Answers

Here is this wonderful thing.
It seems to be a model of some kind of dredge.
It's 100 percent brass and is very well made.
Perhaps it is a salesman's sample
Perhaps someone just made it for his own enjoyment.
I obtained it from an antique store going out of business in Woodland, Calif. The owners knew little of its beginning or history. I was told a person could hook up a garden hose to the tap on the end and that the water would flow through the little piping and exit through the lattice-type conveyor belt, to be ejected through the downward pointing end. Overall, it's about four feet long and three feet wide with both tanks in place.
I can imagine this dredge floating in a pond of its own creation, dredging up gold-filled soil and somehow separating it from the mud, silt and sand.
Am I going off the deep end here? (No pun intended.)
In any case, if you know what this thing is, how it works and why it was constructed in this fashion, I'm open to suggestions.
Have a nice day.