Antique Russell & Erwin Company Bronze Door Plate - Prudhon Pattern

This is a Russell and Erwin Manufacturing Company cast bronze thumb paddle entry door plate with handle. It is part of the Prudhon Collection, which is stamped on the back. Unfortunately, it is missing the lock and thumb paddle. It measures 18" X 3" (a rather substantial front door plate). We found one website that is selling similar plates and another website that sold a door knob from the same collection. 

http://www.coolstuffiscoolstuff.com/category.aspx?CatID=8

http://www.urbanremainschicago.com/late-19th-century-prudhon-pattern-ornamental-cast-bronze-antique-doorknob.html

We actually came across this piece in one of three large buckets of antique hardware we picked up Saturday morning for a very, very nominal fee. Originally, we were looking for hardware to match our 1929 house; but, it appears as though we may we have stumbled across something more valuable - maybe....

If anyone has any knowledge on this piece, please please share! We appreciate your thoughtful comments and any help anyone is able to provide.

Thank you!