[1968 K20]

Hello, was looking for some help on a 1946 or 1947 Chevy COE project I found. The Chassis number on the plate mounted on the firewall is 8PRD 13XX. Was wondering if anyone could decode this or point me in the right direction. The truck looks like a 1946 or earlier but I am being told it is a 1947. He had to file for a lost title and want to make sure. I have posted in the heavy hauler but seems like this page gets a lot more traffic. Thanks in advance