> The supreme court has ruled (almost 100 years later) that it does mean people can own guns, generally for the purpose of state defense [1].
That's not really a fair reading of Presser. That case merely upheld Cruikshank and by extension Barron. Since the Second Amendment was only a limitation on Congress (pre-incorporation) the State could effectively do anything. Presser just added on that States couldn't go so far as to deprive the Federal government the resource of the militia.
> This is the first I've heard of a regular citizen having the right to parade around in their own battleships.
People definitely had their own canons and ships back in the day and it wasn't solely a United States thing [1].