When someone went all-in the front couple of rows of people jumped up to see the table better which blocked the complete view of the table from the people behind them. Unless you were on the front row of the bleachers you never got to see jackshit.
The unwritten rule in those days was the person that moved all in would stand up and stand behind his/her chair....making them ready to make an exit if they lost the hand. Of course, they quickly sat back down if they won the hand. That's how the old school players did it.