Its a Collectors Licence here in the Northern Territory too, but no silly restrictions on owning ammunition.
In this jurisdiction, if you own any firearms of that 'class' then you can lawfully own all ammunition for firearms of that class. ie owning even a single handgun permits the lawful possession of all calibers of pistol ammo.

Some food for thought: if one reads Section 17.1.12 "Supplementary Events" of the SSAA Rules for Big Game Rifle competition, one will find that the banana-benders shoot a "Howdah Pistol" event from time to time. This might be a way to influence your state legislators to allow possession of such hardware for the purpose of burning powder!
If you were to consider pursuing that course of action, I would suggest treading lightly with the full backing of the SSAA State Executive and probably also the BGR discipline chairman, rather than sending the bull into the china shop...