How to tell the difference, K & N, long throw hammer?

[RayGT3]

I'm looking for a pre war, N frame, long throw hammer. What's the best and easiest way to tell one long throw from the other, K vs. N? As I don't have a hammer to match it to. The gun has a butchered up "custom" hammer on it. So I really don't know what the origonal was supposed to look like.
TIA

Ray