Visor vanity mirrors
 

Recently I got the phs back on my 64 lemans. It said that it can with mirrors in the sun visors but when I look at the original visors there is no holes that the screws would hold the mirror to in them why is this?

vanity mirrors were clip on & had pontiac print at the top

Yes, the screw on style didn't show up until sometime later (early 1970s?) If the clip on mirror was in place for any amount of time there should be permanent dents in the visor edge from the clips.

Visor mirror
 

On my 1964 Bonneville D34 on the build sheet. 2 screws hold it in place. maybe someone replaced your visor. Example https://www.ebay.com/itm/18512384802...IAAOSwlj9eBkCt