On a very similar note, it would also be good to edit the order number so that it can match up with in house order numbers.
At the moment, the order number is just the primary key for the PayHist table. Perhaps it could be an independent field - programmers always love using database keys but they are really ugly identifiers (that goes for URLs too). Also, it can be embarrassing when you open a new store and some customer gets order ID "3", for example. Makes the seller look really unimpressive.
Also not a show-stopper.
@gbaughma - what happens if you change the product in the database table? I assume that'll work, albeit not a viable solution.