The casting numbers indicate that the block is a 58 283. That being 66 years ago, who really knows what is going on now. At least as far down as the rockers and valley it appears stock.
I ran a borescope in the center of the pulley to see what was going on when I didn't see a bolt head and it sure looked like a sheared bolt.
I assume that the end of the crank would have been machined and not left as-cast? Picturing it in my head, it *could* have been a rough cast surface, but I don't think so.
I think I will just run it as-is and keep an eye on it.
Thanks for the info!