On the rifle I use for target shooting, I enlarged the notch on the 1902 sight just enough that I could see a little sliver of light on each side of the front side base.  I also thickened the front blade with electrical tape.  Still, the front blade gets a bit fuzzy when I pull it down into the notch, so lately I've been experimenting with leveling the top of the front sight base in the notch of the rear sight, leaving the blade up where I can still focus on it.  Seems to help, though I've only shot it a couple times that way and haven't got my 100yd zero yet.    Next time you get a chance to shoot try an SR1 target using a 6 o'clock hold with the front sight in focus, target left fuzzy.  You can find the SR1 targets online and print them out on 8.5x11 paper.