Recognizing Winchester front sights???

My literature says that Win front sights can be unmarked, coded L, and some or all have a thumbnail cut behind the blade. I have also read that Win front sights have a different curve on top of the ears that the other sights. 

In the photo, the sight on the left is unmarked, has no thumbnail cut, but appears to have the distinctive Win curve to the top of the ears. The two sights on the right both are unmarked and with a thumbnail cut. The ear top curve on these two seem to be the same as the one on the left. So, I am thinking they are all Winchester. 

But I also noticed that the pin hole on the left sight is more in line with the large ear hole above it than the two sights on the right. Those pin holes appear to be offset some more to the rear than the one (unmarked with no thumb nail) on the left. I do not know if this might have meaning in determining what the sights really are. 

I would appreciate your opinion, and any other info that might help me ID these sights. Many thanks.