FYI, I came across a single action five shot 38 caliber top break revolver, (4" barrel) resembling a Smith & Wesson DA. Knowing nothing about such an animal, did some basic research. It appears to be a Spanish Counterfeit: Smill & Wilson Sprangfield, MUS EUA
with patent numbers from Jan 24, 63 to Jan 9 87. It has a poor quality 38 cal stamp on the left frame and a number 17 stamped on the top of cylinder and also under the sight.No other markings or numbers. The build is very poor. I would never fire it. Thought my eyes were deceiving me on initial reading of the stamping. Clever builder, apparently they were hoping nobody could read english in their market area.
Just posting to share the info.