Re: How to fill sight holes
What are you trying to accomplish?
If you are going to coat it with a bake on finish, fill them with devcon or similar material and file it down.
The other option is to find screws that fit the holes and if you can't, then tap them out to something you can.
Insert, cut off, then smooth. I like to leave them a little proud and peen them down slightly before smoothing and polishing to help hide the thread.