Fostoria # 2373 Window Box with silver deposit by Rockwell Silver

I recently acquired this beauty and have finally identified the maker as Fostoria Glass. It is a black glass "window box" known as line # 2373. I have yet to see one in black glass. The added beauty of this item is that it has silver deposited on both the planter base and the matching frog. The silver work was done by Rockwell Silver Company.
I am trying to find out what the pattern is on the silver deposit and what the value of the piece is.