Based on this information from the BD website for the Wellington 3.0, you fit a 56cm frame.
56mm53.5mm560mm1000mm31"420mm7373
Your inseam (if you are sure about that) is well above the 31" stand over height of the top tube.
Having said that, you can also go with a 53cm.
If you truly have a 32" inseam barefoot, you will have a true inseam of nearly 33" when wearing clip on shoes. You can go either size and tweak the stem to a longer or shorter stem to match your torso height. It's your call. I suggest you go to your nearest Performance Bike store and look for a road bike with a conventional triangle frame (any of the Scattante's will do). Now find one that is sized as a 56" and see how you fit on it. Now find one with a 54cm and so on. Maybe have one of the guys in the store help you find the right size. This is the best way to be sure what size is right for you before you leap and make a purchase online.
Another option is to simply email BD and get a definitive answer. Because you are in between sizes, the right bicycle size will vary based on frame type and frame maker.