Neil- As you should fully well know, you cannot compare a picture to a drawing. The presumption apparently is that you think the drawing you linked on the McMurray site is representative of what their birds look like in reality. I assure you, it isn't (but, I imagine you already know this).
I have raised ducks for 20+ years and I have *never* seen a hatchery/production Rouen with the type represented by the picture in your link. Seriously, only in top exhibition birds do you get that type (in the US). Rouens in the US simply do not have that type. Only a very select number of breeders have birds that are that typey. The vast majority anymore simply look like overgrown Mallards. That is production/hatchery quality. To assert otherwise really is borderline ludicrous.