It might have been your post about the set screw that I read.
This is the one that I bought. 
517470   Manufacturer: U.S. Military 
Springfield 1903, Springfield 1903A1 Front Sight Assembly (Assembly Required) 

I also bought the pin and spline.  There's a slot for the spline that does intersect with the hole in the back of the sight.  The pin they sent me is way too big for the hole.  I'll call Numrich tomorrow.
I'll call CMP to see what they offer in this area. I like the looks of the sight.  If it comes down to it, I'll try West Systems epoxy - it's holding my sailboat together.