If you have the crack on a well worn 1914 buffalo, the one that is distinctive for the 1914/3 buffalo does that indicate that its the overdate?
I would say no. Since they all have the same basic design, cracks or other die defects tend to develop in the same area of weakness. I realize that the TPGs and Heritage and Lange et.al. have said it is a 4/3, I will always have some doubt , but that means little as people still pay big bucks for them/IMO.
I'm not aware of a die crack that is diagnostic for the 14/3 Buffalos, and frankly since they come from more than one die I don't think there could be one. I think you are confusing it withthe 18/7 overdate which DOES have a diagnostic die crack. And yes the services (or at least ANACS) will authenticate even a dateless piece if it has the crack.