My name is George and I need help to identify a gun that I own. A Marlin 336 was given to me as a gift many years ago by my son-in-law. The gun is stamped on the barrel Model 36, the barrel is 20" and the forearm has a steel cap instead of a barrel band. the magazine extends roughly 1-1/2" beyond the forearm. Now the question is about the seriel number it begins with a Z designating a 1963 manufacture date??? was this gun rebarreled or did Marlin make guns using old model 36 barrels? And if so do they have any collector value? The specs of the gun match a 336SC but the barrel is stamped Model 36. Thanks for any help.