Interesting piece. Has features similar to other designs, but would seem to be unique. The mechanism is generic; pivoting trigger, disconnector on the left side above the grip, pivoting internal hammer. Doubt that the number is a true serial, in the sense of starting at 1 and going from there. If that many had been made, the pistol would be identifiable. Hard to say if everything is original, but note the Phillips head grip screws, and the roll pin at the end of the slide. It would be interesting to see a photo study of the pistol, including disassembled views. It would seem that some machine tools were used in its manufacture.