What a great find!!! Thank you for posting it on the ALR. You appear to have a fine New England fowler, and it is a real plus that it is a family held gun. Would not be surprised if this gun was used in the Rev War.
The fore end looks like it has been cut back and a bayomet stud put on top of the barrel. Look around some more, you may find something else applicable to the gun. Lock looks English and has the' bee' on the cock and a 'bellflower' on the plate. The mark on the barrel may be 'Z 1', or conversely '12,' or '21.'
Very likely the gun was made up in your area somewhere around, on or before the War. It would have served well for a time as a militia arm for a Minuteman. Nice that it is a good 'as found' condition and I would not do anything to it to 'improve' its looks. You might post some additonal photos of the various details; the butt plate, rear entry pipe, the muzzle and so on. You will get more information from the folks here on the ALR.
Thanks again.
Dick