Hi, I recently purchased a model 64-3 stainless with some markings I am not familiar with. Can anyone help me? The gun is sn AJL8860. It has the following stamped on the bottom of the butt- T61 over KNOX TN. On the left of the frame under the grips is stamper a large S. I assume that is for stainless. On the right frame under the grip is a circle with a R in it. Also a triangle with an x in it. Any help will be appreciated. Bill Hughes