The hinges I have seen form Airstream come with all three pieces already attached. Inner and outer hinge for the door and the intermediate hinge for the screen.
I do not know if driving out the pin and replacing it is the best route to go as the aluminum will likely expand when you do this and the pin may not be able to be driven back in to a fully seated position. Making the door loose on the hinges
The hinges themselves are a standard item from what I have seen, but I do not have an exact cost. There is a difference between the upper and lower ones. I also know the hinges are the same ones whether you are talking classic MH or trailer. They are just reversed. on a MH the one that is marked L goes on top.