It represents USS Alliance in its later role as a sail training ship. There are quite a lot of changes from the original gunboat fit, such as the funnel/stack being reduced in height
The Pyro kit's representation of the armament is very odd; in addition to the numerous small breech-loading guns on the main deck (presumably for saluting and firing/loading practice) it has a large number of "broadside" gun barrels in the gun ports in the ship's side, which I suspect are actually simply hatches; I don't think Alliance ever had a gun deck like this. The best solution would probably be to leave out the kit gun barrels and scratchbuild covers for the hatches from styrene sheet.
I'm not sure what other "issues" there are, as I could find very little reference material on the real ship. The level of detail and moulding quality is fairly reasonable, though the hull sides and some other parts have overscale and rather unconvincing "wood grain" moulded in. And (if I remember correctly) it has the sails moulded integrally with the yards, like most other Pyro kits - though, in my experience, it isn't too difficult to cut away these moulded sails.
The stated scale is 1/200, though I haven't actually measured the kit and compared it to the real ship's dimensions.
Certainly not one of the better kits out there, but for the "sail-and-steam" enthusiast (like me!), it might be worth buying if you can find it cheap and don't mind putting some work in to fix and improve the kit's shortcomings.