I have what I believe is a Model 36 RC 30-30. However, the serial number has no letter prefix and it has Model 1893 on the tang. It's a beautiful gun and in pristine condition. It also appears to have a custom stock. This was my Grandfathers hunting rifle. It was drilled for a scope at some point, I removed the scope. Anywhere else on the gun I can look for clues as to what it is?