Main bearing question

When I was a kid I knew a guy, John was his name. He had a newspaper route that he worked with his Renault Dauphine. Went with him one night on his paper route, and while still 25 miles from home, the Renault starting rattling and losing oil pressure. He pulled over to the side of the road and said, "Don't worry. It does this all the time." He jacked it up and drained the oil, pulled the oil pan and figured out which bearing had let go. Went to his trunk and got out a box full of bearings. Installed another bearing for the bad one, put the pan back on and reinstalled the old oil. We finished the route and got home fine.

You just need a box of bearings, even used ones should work.