I talked to a guy I know who used to work there. They definitely do not use any orange peel or zest or anything in the amber, or any of their beers for that matter. He has seen the recipe, and said that all of the clone recipes he's seen are way off (every homebrew shop in the area has a recipe). He says to use lots of crystal, but he thinks the real key is the house yeast, although he doesn't know what the background of the yeast strain is.
Of course the goal is to clone the flavor, so if you think using orange peel gets you closer, have at it.