from what I have been told over the years if you are related to the owner of a now prohibited pistol you can inherit it due to being related ??? you might want to look into that.
my buddys father inlaw passed away in Toronto last year and as soon as he was prononced dead at the scene the police wanted to take all of his safely stored guns away from his home. they phoned me right away to ask me my opinion and I told them to inform the police that the executor of the estate has 1 year from his fathers passing or a reasonable amount of time to dispose of the said firearms.
so he has the same rights his father had. so the police were told to get lost. this happens quite often from what I have been told.