Replacing 67 Cuda front wheel studs - not so easy

I am having an experienced guy do the brakes on my 67 Barracuda. I was going to have all the studs changed to right hand threads. The back studs went pretty easy, and I furnished the studs that are supposed to be correct for the 10" drums. But he said they didn't fit. They were too loose.

I've done a lot more reading on this and it looks like the studs are originally put in through the hub and the brake drum, and then flared out to hold the two parts together. Now if the studs need to be removed, a cutting tool is needed to cut off the "swedge." I understand that -- NOW.

If the stud is just pounded out, the flare will enlarge the original hole -- and this is probably why the proper studs are too loose now. I drove the car home with just 4 of the original LH studs until I can get this figured out. Maybe only one hole has been enlarged.

The correct studs (7/16-20) have a knurl diameter of 0.555" There are two more options of 0.563" and 0.570." The lengths are slightly different.

1. If all the holes are enlarged, could a larger-knurl stud be installed?
2. If all the studs were properly replaced, how do they get re-flared? Or does it matter?

Maybe I should leave the front LH studs in, and not change them out.

Are Ford and Chevy front wheels made this way? Should the guy have known about the proper way to remove studs?

Any advice would be appreciated.