Not sure about the "Hawken" designation either. Sorta a generic looking muzzle loader. But, if well made, and it looks fine, should be OK.
I don't like the use of a flask for loading or placement of it while shooting, especially with a flintlock. Bad-bad safety issues there.
On a farm with no tools?
Gimme a break.
You can use wood or a nail to drift the sight.
Again, a farm with no files?
Gimme another break.
Grouping at 25 yards is not bad but you need to be using a 50 yard target to really establish whether your ball/patch/lube/load combo is providing the best your rifle can do.
Then, and only then, start poinding and filing on those sights.