Antique guns are fragile, parts are hard come by (kinda like old folks). Shooting them is somewhat abusive as it does wear and adds stress on tired iron. So, and I can't believe I have to explain this, the forces of recoil can damage wood that's already shrunken with age. If you love your antiques as you would a grandparent, treat them kindly and gently.
Having said all that, it's a gun and the times where we could trade them are gone so if I can get an antique, there's an argument for using it to the point of failure or disrepair? "Granny may brace herself for a sh1tkicking.".