A Bing search found pictures of a couple of the W.H. Davenport double.
Early Hammer Double 01.jpg
Early Hammer Double 02.jpg
The only W.H. Davenport Fire Arms Co. catalog I have contains only single barrels, like my Maternal Grandfather's ratty old single in my safe, but included folders for both a hammer and a hammerless double of more conventional design.
780 02.jpg
I've yet to see one of their hammerless doubles.