I have a razor that needs a set of scales. I was thinking of ordering a set from Superior Shave. I haven't put scales on a razor so need some guidance.

The hole for the pivot pin is a little large: I can put a coat hanger through it which is about 2.2 mm. The hole is also not round. Do I need to drill this hole out, or can I use it the way it is? I was also thinking of ordering a hex bolt with the scales, since the hole is large. Are these a good choice? I have tried to look for a video on attaching these, but assume I would peen the bolt after I cut it to length the same as a pin to keep it from turning and loosening?

Thanks for any help and directions