I started using power tools by the time I was 5 years old and went to work plastering for my dad when I was 14 durring vacations but I knew the rules and kept my mouth shut and of course never applied for their stupid permit which would have been denied because of the work I was doing.
When I was 12 the kid up the street and I worked on weekends rebuilding D-8 Cats for his father.
I also drove my first flathead rail at Santa Ana drag strip to 128 mph when I was 12.
This sounds like the America I used to know. I did much of the same and would allow my children to do so also. I would also use what I have learned to make them more safe, always use blocks and jackstands, (I didn't always) never work on an incline, never use gasoline to wash parts (I did) always use correct gloves, eye protection, and clothing ect.
We can't make everything perfectly safe, and kids need to learn to work and deal with risk maturely that's how they survive both as kids and adults.
This guy should take his kids off the high risk jobs and give them other work till they are 16 and trained and the state should take that and leave him alone.
The whole thing boils down to a process similar to aging fine wine or meats; when is it time to set the table?
That puts you in a different class than the 'master of the house' in the story posted. He taught his kids how to work without the burden of all that safety equipment. I wonder if he has life insurance policies on his boys.