I recently acquired a Model 64-1. Serial #1D6XXX. It has a 6-inch barrel and the barrel is stamped 357 Magnum. The barrel is pinned, the cylinder is recessed. There are 2 screws on the side plate and 1 screw to the spring. And it is stainless. There are different numbers on the yoke they are 164XX. I have read a little about the Oklahoma State Police getting the 64-1, in the early seventy's, can anyone help me with additional information? I am confused by the different numbers on the yoke and inside handle?