The truck has been in my family since it was new. The hole appears to be broken out, not torch cut. The metal around the hole does not appear that the hole rusted away. It looks more like it was the result of a crack that eventually broke out.
This, combined with some other things I have found, makes me wonder if the truck was in a wreck at some point early in it's life that I don't know about. This is what I have found...
1) The outer corner of the left front fender was at one time fairly seriously crushed, because it was hammered back out, but the finishing body work was never done. Also, the left headlight assembly appears to be a replacement.
2) The hood latch panel is painted blue underneath, the truck has always been red.
3) The lower grill panel is rusted through along two very defined creases, that appear to be places where the panel was bent and then straightened.
4) The front bumper has a slight wave, just left of center, that could be a sign it was bent in, then heated and pulled back out to almost normal position.
5) The grill bars are beaten up, could have been caved in and then sort of straightened back out. More so on the left side of the truck.
My theory is the truck took a pretty good lick on the left front. The impact point (by the height of the fender damage) was about headlight height. This pushed the top of the grill, hood latch panel and radiator support back. The force could have cracked the crossmember, maybe not breaking it out at the time...vibration and movement broke it out over the years later.
For this theory to be true, the hood would have also been damaged. The truck has a solid mint condition hood...perhaps a replacement.
I do have a very vague memory of the truck being worked on in the FFA Ag Shop at the high school. This was when I was a small child, my memory is going to the shop on a Saturday and watching my older brother and his friends mask and paint the truck. This would have been around 1969-70ish.
No one is left who could tell me what happened, so I just have to make my best guess based on what I see.