Front end wont stay aligned

I drove my 65 when the steering mount darn near broke off. It was cracked on 2 of the 3 mount planes. Imagine speed wobbles on a skateboard, but its your entire car! It happened at about 15 mph and you would have to brake hard or the car would feel like it would shake itself to pieces. I drove 5 miles home at 10 mph. On a lighter note, check the idler arm and centerlink pivots. They wouldnt cause an out of alignment but would make steering sloppy.