The 16g hammerless was not introduced until about 1896.
There is lots of information in the FAQs, including recommendations regarding refurbishing or restoration
Unless a high grade gun, the cost of a full restoration will far exceed the value of the gun.
Please be aware the the chambers were originally 2 9/16"
Obviously the gun needs to be evaluated by a double gun specialist smith. If you will let us know your location, possibly we can recommend someone nearby.