The original interpretation is, quite frankly, largely irrelevant, because the entire BoR was written in the context where the chief concern was guarding the rights of states against the federal government. With 2A, they wanted to make sure that the feds couldn't suppress state militias, as the British tried to do. When it came to the rights of citizens against their respective state governments, that was what the state constitutions were supposed to protect.
But, conversely, the very notion that the federal government would even be able to ban state citizens individually from possessing arms would be just as alien to the authors - the constitution simply didn't grant that kind of power to it back then, not even close.
OTOH the notion that the right to keep and bear arms was widely perceived as individual by the American society as a whole has solid historical basis. Here's one simple thing anyone can do to verify this: go look up the list of 2A-like clauses in state constitutions, along with dates they were adopted:
https://gun-control.procon.org/state-constitutional-right-to...
You might notice that the earliest examples often specifically talk about individual rights, e.g.:
“The right of the citizens to bear arms in defense of themselves and the State shall not be questioned” (Pennsylvania, 1790; Kentucky, 1792)
Such language becomes rarer over time, though, until we get to the end of the last century.