Have you check out Kesselrings in Burlington? They usually have a lot of different shotguns and stuff in there, and if you are looking for something particular you can tell them and they will call you if something comes in that they think you might be interested. There is a new shop in Anacortes just past the Swinomish Casino at the top of the hill too, might be worht checking out if your around the area.
Apparently we have to be a dealer to buy one. It is not too much of a worry as they appear to be more expensive than we can get here, especially the Perazzi. We would like to stockup on pads etc that at that moment we ship out from USA.
There is also Greenes Gunshop on Whidbey Island near Decption Pass and also Ace Hardware in Oak Harbor, I wouldn't go to either of them looking for a trap gun necassarily but might be able to get other supplies that you need/want.