Scott,
Welcome to the board.
One of the other guys will know for sure but in the time I've been here, I haven't heard of anybody that has a mortar that big.
While it would be cool, there are several things that would keep me from owning one:
1. The tube alone weighs almost 1900 pounds. Add the base and you're into the 1 1/2 to 2 ton range. Transporting it would be problematic at best.
2. It uses LOTS of powder which gets expensive. (During the War of Northern Aggression, a war shot was 4 POUNDS of powder behind an 87 pound exploding shell)
3. You need a REALLY large area to shoot it. (Range with the stated load was 2100 yards which equals 1.2 miles)
4. 10" ammo (solid) will be very difficult, if not impossible to find.
5. The most important thing though is that the mortar you mentioned is a
antique and very likely wouldn't be safe to fire.
A while back, South Bend Replicas cast an 1841 10" Seacoast mortar for a special order. Call them and talk to J.P. Barnett the owner. I'm sure he'll be happy to fill you in on all of the details.
If you decide that starting out with something a bit smaller and less expensive is a good idea, we can certainly help you out.