From the Gallery, this pistol shows that the thicker body carried over into version 2? Doubt it was for long but would love to know the serial number of the pistol. This pistol has the early breech bevel and the flatter body where the tube is attached, characteristics of the early frame. But has the new rear sight of version 2.
Below is the crease where the body joins the barrel characteristic of the change to the thinner pistol;