Carl, thank you for the effort of you put into precisely measuring and weighing those balls, in response to my question. The data you've provided confirms what I discovered when I precisely weighed and measured a cache of RevWar cannonballs that got dumped into a river here in Virginia. (That is why asked you for precise measurements of your RevWar group.) Cannonballs from the Colonial Era tend to be a significant bit smaller in diameter than Mid-1800s cannonballs. Apparently, the increase in projectile diameter is due to advancements in metal refining and cannon-casting that resulted in "stronger" cannon metal, which could withstand the increased bore-pressure created by smaller windage.
Regards,
Pete