Paul Revere Reproduction Bowl F B Rogers. What is is made of?

I found this bowl at a garage sale for 50 cents and though it might be a good casting material. I would like to know what it is made of though. Mine is not in as good of shape as the one pictured on the right.

What I know:

It does not specify silver on copper or sterling silver so I do not think it is one of those.
It is heavy. A rough estimate of density of the base is 9.5 g/ml
Lead — Density: 11.35
TIN — Density: 7.287
Zinc — Density: 7.04
Nickel — Density: 8.912
Copper - Density 8.96

The base:
It is dull gray color in the middle.
It is silver plated. I would guess pewter. I melted it down and cast it into this lost crayon casting

The sides:
Under the silver plate it looks a little yellow like a brass or other copper containing metal.
I would guess brass.





Please comment with your thougths. Or reply at this forum.
Whatever it is made of it seems to be a pretty good price at 50cents for 1.5lbs.