At least it is to me. I have heard that some were stamped model 60 (I may be wrong) and some came with no model designation. I know there was a limited production run of this model. The one I have is S/N 931JXX with model 50 stamped on the frame under the crane. According to what I have found that a little over 1100 were made with this S/N series. I removed the grips and the main spring is a coil spring which surprised me. I have not encountered this model before and I want to be sure of the rarity. The revolver is unfired with the box and original receipt where my step-father made the purchase back in the 70's. The reason I ask about this revolver is that my 96 year old step-father insists on being able to open the cylinder and operating the double action but he doesn't have the hand strength anymore. I refuse to modify the revolver. After reading up on it some it became apparent that this model is more complicated or I've been misinformed in some way. I would really appreciate any information on this model.