This has me thinking that you may have seen a '67? taken apart and repaired, I am not familiar with the '67 or '69 grill surrounds. Sounds like the stud hardware is different than the '68's!
After removing my stud, (as you described), (ALL) The hole on '68's are round, doesn't really supersize me, just about every other part on these cars are a little unique in one way.
I agree with there is more than one way to skin a cat! (as far as how-to repair these parts)