When I bought my first two they looked the same but one ended up being a khaki Campbell which to me seems similar to what you have here. The down was always a bit darker than the other which is a Pekín. But maybe you have a Pekín too!
So turns out, mine is not a Khaki campbell but looks to be a Buff? so weird. I have a couple of books that you may want to get. I've been reading both but one more then other and they are fairly cheap on amazon. "Duck Eggs daily" Lisa Steele and "Raising Ducks" by Dave Holderread. Duck eggs daily has a lot of great stuff from duckling to adult hood. Can't put it down!