Looking for a smoothbore flinter for hunting birds, rabbits and maybe deer and have narrowed it down to these two a Pedersoli Mortimer 12ga or the NorthStar Officers musket , which one would you choose and why.
I would definitely prefer the "style" of the Pedersoli Mortimer, over the longer barreled musket, especially for bird hunting. A half stock, English sporting gun is a much better choice for your bird and rabbits over a musket. Both guns can be loaded with ball, but I would give a slight advantage to the musket for deer hunting due to it's heavier weight and longer barrel for aiming.
As others have mentioned NorthStar is a very good quality gun and company, the Pedersoli is ok. If you ever need a spare part, heaven help you if you need to get one from Pedersoli.
If you really are serious about your bird and rabbit hunting, I would try to find an English sporting gun, or have one made. Or as a second choice, look for a light weight full stock fowler. It would be lighter than a musket, but it would have the same disadvantage for upland bird and rabbit hunting, by having a long barrel.