$50 is a really good deal for the gun, even if it isn't in the best condition.
Like the others mentioned, it is a "brass frame" pistol so keep the powder loads on the light side.
These cap & ball revolvers use balls that are bigger than the bore so even though it is listed as a .44 caliber, it uses .451 to .457 diameter balls. That will result in a small amount of lead getting sheared off of the ball when it is rammed into the chambers. It is this shearing that causes the ball to make a tight, "line to line" fit with the chamber which is what keeps the ball in place in the remaining chambers when the gun fires.
As for the actual gun's design, first off it is a reproduction of a Colt 1851 Navy. It is also a reproduction of a non-existent gun. The 1851 Navy was a .36 caliber pistol.
The Italians got the idea that people would like a .44 caliber version of it so the created a "rebated cylinder" by making the forward end of it larger so it could have .45 caliber chambers in it. They also added a clearance cut to the frame to allow this stepped cylinder to fit. This sort of thing is exactly what Colt did when he created the .44 caliber 1860 Army revolver.
Although the gun is patterned after the Colt 1851 Navy which is a steel frame revolver, by making the frame out of brass, it is actually more like the Confederate copies of the 1851 Colt. The Confederates were the only ones that made brass framed revolvers.
I know your going to have fun with it.