Many of those cards never made it past the '60s. Mom threw them out. They were given away. Those that survived weren't exactly 'mint'.
Some guys always knew where their cards were, though.
There were too many memories attached to those shoeboxes.
Some eventually replaced their old beaters or put them in plastic sleeves, but still kept them stored the simple way, ready for the dust to be blown away and the great memories to come back.
Carolyn Hall-Jensen put together a well-produced piece at one home of a die-hard collector: