If you want to shoot it.....must be registered and licensed for that purpose, doesnt matter about manufacture date...stucks of perfectly functional and safe rifles from pre-1900...
IF the rifle is of an obsolete chambering and pre 1900/'antique'... (and I recall VICPOL had a list of what they consider obsolete, which included damn near everything you could or couldnt imagine....old BP rounds no-one has heard of since or ever etc etc....) then it can be licensed as a collection piece and can NOT be used. As in NOT fired....
I dont think it has to be de-activated though
edit to add; in the real world 'obsolete' means not in commercial manufacture.....not to the (fun)Police.
It is almost comical, registration of these old firearms, that although could injure someone, have probably not been used in the commissioning of a crime since about .....never..well maybe the mid 1800's...but all the rego and other laws apply...