There's another alternative, if any of the orignal pin remains. After I removed the bayonet from my M44, sawed off the lugs, and ground down the remaining metal into a neat ring, I took it out to see how it shot. At 100 yards I was shooting about three feet high. I went into a local crafts shop and found some straight plastic beads. I reamed one of them out enough so I could force-fit it on the orignal sight pin and epoxed it in place. Then, by carefully cutting it down at the range, I reached the point where I was pretty well zeroed at 100 yards.
Now, after a couple of hundred rounds the plastic fell apart. I then scoped ithe rifle and didn't worry about it. But I'm thinking if you found a hobby shop which specializes in model trains, you might find a small hollow brass tube you could force-fit over what's left of the original pin (again, if there is anything left at all). Even if there's only a little nub, you might get it to hold by using epoxy or Plastic Steel.