Two guns come to mind, a 12 gauge percussion double barrel shotgun and a Marlin 1881 .45/70 lever action rifle.
Not sure of the exact production date on the shotgun, probably built sometime in the late 1800's. I don't know exactly when it was purchased but there is a record of it being in the family before the turn of the 20th century.
The Marlin was purchased in Wisconsin in the 1880's by my great-great-grandfather. It has seen better days but is still in working order, my dad took it out and shot it last year.
We have several other guns that are nearly as old, including a single barrel 12 gauge that my great grandfather carried from North Dakota to Washington state when moving (by wagon) in the early 1900's. Eventually made it all the way down to Trinity/Humboldt counties in Northern California.
My Dad's side of the family were mostly farmers so lots of old inexpensive shotguns, mostly old single shots meant for low brass shells. Some of them are in shootable condition, some are not. We also have a number of guns from the first half of the 20th century some of which may have a bit of collector value.
So nothing extremely old, but still some interesting guns. One of these days when I get together with my dad and my brothers we will have write down what we know about each one to try and save some of the family history for future generations.. There are some interesting stories that go along with a few of those old guns........