They have not been converted to electric or gas. They stand about 3" away from the wall and the back plate is 1 5/8" x 5 1/8" - the screws are approximately 3 38" apart. They do have some condition issues- I could not unscew one of the the sconce bottoms.One glass piece is thicker than the other and probably was replaced. 2 tines are missing on one sconce- see photos. The item "Vintage Pair Of Railway Train Carriage Wall Sconces Candle Brass Glass PLR Paris" is in sale since Monday, January 25, 2021. This item is in the category "Antiques\Architectural & Garden\Chandeliers, Sconces & Lighting Fixtures". The seller is "pattigearing" and is located in Vernon-Rockville, Connecticut. This item can be shipped worldwide.