As others have said the pictures are too small to be much good, but I think it's a S&W Military & Police model, also known as the model 1905 Hand Ejector, If so, it will not be marked with a model number, and could have been made anywhere from 1902 to 1946. The serial number should be stamped on the bottom of the butt, the rear face of the cylinder, and on the bottom of the barrel above the ejector rod. To see the last two numbers you will have to swing out the cylinder, and they should match the one on the butt. That number may have a letter prefix such as "V".
I also think that the barrel has been shortened from one that was longer, and the front sight replaced - followed by a nickel plating job.
I would advise that you don't buy it for any price until you have a correct identification.