I noticed on one of your wall sconces a clock on one side and lamp on the other, how interesting. Would that have been some thing available to the period of the house or some thing cobbled up, sort of a steam punk thing? I have never seen one.
My house was built in 1922. This was way too late for gas lighting. When I moved south I brought all my gas lights with me and piped in the black iron gas lines. I have two sets of gas/electric wall sconces. The early electric companies were prone to shutting down so gas was used as a back-up. This style fixture was rendered obsolete once the power grid became reliable. The gas light clocks were a novelty item. The clock holder fits over the tube which houses the ceramic burner. These clocks can also stand on their own on a flat surface. Waltham gas light clocks are the most commonly found. If I'm remembering correctly, the movement is a 14s 7 jewel movement.