No idea at all where you're going with that.
Postulating on how many firearms Gage confiscated. Based on the population figure you threw out there coupled with known census numbers and if census numbers were based solely on heads of households.
Well I think I found the confiscation numbers. According to this website
https://davekopel.org/2A/LawRev/american-revolution-against-british-gun-control.html
“On April 23, 1775, Gage offered the Bostonians the opportunity to leave town if they surrendered their arms. The Boston Selectmen voted to accept the offer, and within days, 2,674 guns were deposited, one gun for every two adult male Bostonians.”
Of those who were involved in offenses in Boston to the crown (The Minutemen) but not the entire population of Boston.
Interesting read.