I'm gonna drive her there. Wish me luck!

 

I hate to say it but it looks normal to me. Look under another car and compare. It could be alright.

 

That pigeon poop weld is broken at the frame rail. The weld itself should not break. The steel around the weld should tear.
It appears to be the original factory weld, it just didn't penetrate the frame rail correctly. Might be the only poor weld, but it would be worth investigating. The guy welding that day could have had a hangover.
*********edit
I just went out and looked at the same place on my car. There should be a flange on the frame rail that is spot welded. Not a butt end that is welded. So that may not be a factory weld after all.
**********end of edit.
As Dodgestang said, the car needs to be pulled together, and checked for straightness before rewelding. Look for thin rust trails around the other welds from around that area of frame rail. Of course after 40 years, you may need to clean the frame down and mag the welds. A quality frame shop should be able to point you in a cost effective direction for repair.

I doubt the car will fall apart on the trip over. Who knows how long it's been like that. Doesn't look fresh.
Good luck,