I have a Winchester carbine in the 5 million 7 hundred thousand range. At the end of the serial number there is a "D". What does this mean? Also it has a dog bone shaped cut out for the oiler and strap. It also has a W.R.A. Over G.H.D. I thought these dog bone stocks were only for early Inland carbines. What's up with this carbine? Thanks for any help..