A couple words of caution....
Already mentioned, the chamber length. 2 9/16" was a popular length before 1900, also.
And, be absolutely certain you do not have twist barrels. We call all twist barrels "Damascus" today, but in those days, only barrels made from 6 or 8 strands were worthy of the name "damascus". Guns made with barrels formed from 4 or 2 strands were known as "stub twist" or just "twist".
And "twist" barrels may not show the typical "damascus" pattern, leading them to be misidentified.
Solid barrels were a pride point in marketing when they came out, and most makers marked their barrels or pointed out in their literature that they guns had "nitro", or "fluid steel" barrels. Nickel steel was another name used a few years later.
I have an Ithaca Flues model, bought new by my grandfather in 1909. It has fluid steel barrels. He bought it to replace a twist barrel gun he sold to a neighbor. That twist barrel gun blew out in the 1940s!
I still shoot it sometimes, and ALL I shoot is either 3dr eq target loads or 3 1/4 dr eq. field loads, like the Remington Shur Shot. LEAD SHOT ONLY!!!!!!!!!!!!!
Because of the advances in shotshells, beginning in the 1950s, (plastic shot cups, etc.) older guns pattern extremely tight with modern shells. They are choked tighter than more modern guns. Grandpa's test for a full choked 12ga was that a dime would balance in the muzzle. GO get a modern 12 ga, and a dime falls through a full choke. Shoot steel in a full choked old gun, and you might just blow off the choke! Stick with lead for all the older guns.
I have a letter from Ithaca, dated 1949, to my Grandfather, he had writen them asking about the guarantee on the springs. They wrote back, affirming that the springs were guaranteed never to take a set. The letter also included a message from the VP stating that he should not use "Express" type shells in his gun. They were not needed and were "akin to using a bulldozer to thread a needle"!!!
Assuming your gun is in good mechanical condition, has 2 3/4in chambers, and does not have twist barrels, modern lead ammo in the 3dr-3 1/4dr eq range should not hurt it with occassional use.
If your gun does have twist barrels (of any kind), stick to blackpowder loads only, and stay on the mild side of them, for safety. Twist barrels can develope rust in the welds between the strips, where it is not visible to the eye, and you could have a very weak barrel that looks fine. I would hang a twist barrel gun on the wall. A gun with fluid steel (bored steel, nickel steel, etc) barrels still deserves a walk in the fields, once in a while.