Your EPNS stuff will be worth 1 or 2 dollars at most. It will cost you more to refine it. you have to be dreaming if you think you got a few ounces of actual silver. The layer of silver is microns thick. So very very little. Heck, you might be able to sell it more in its current form!
At least you have the solid sterling stuff. I would personally keep it as is. Something about silverware that is too pretty to melt.