I had this happen with another revolver - I ended up going to the LGS, getting a couple different sizes of glo sight rods, finding which fit best, and then epoxying it in. Set a nice little bead of epoxy and pressed the rod right into it. Worked very well. I don't recall what size it was... but at a couple of bucks... doesn't hurt anything.
The ones I got were meant for shotguns, trimmed it down a little bit, but there are a few out there. I'm sure a simple search on midway or somewhere would bring up lots of stuff. Search for "lite pipes"
