To me it looks like a classic case of the early signs of the "tactical virus". If left untreated, a growth that resembles a scope will grow on the mount and in its classic form, will have lots of controls on the outside with multiple cross hairs and such on the inside, and in a short while the entire firearm will develop a dark green to matt black colour. If this disease spreads to the shooter, he will develop an uncontrollable urge to wear camo clothing everytime he goes bush and in extreme cases will even wear a gilli suit. The desire to get close to his quarry will, in most cases, leave him. He could even start to believe that hunting game is akin to war. The best treatment I know of to ward off the tactical virus is to just grab an old 22 single shot with no scope and walk a paddock shooting a few rabbits and remember when you were a kid.