That stamped number is the only thing that means anythng on that plate as far as the state is concerned.
When I moved back to Washington my door post plate had about 8 layers of paint on it and the state patrolman who was the inspector took his knife and scraped away the paint over the serial number and that is the way the plate is to this day.
The state is not interested in the printed info on the plate, they are far more interested in the fact that the original rivets are holding the plate on and that it has the correct serial number.
This is a 51/52 door post plate repro.
If you have a title and the number doesn't match the door post it shoul match the serial number on the engine block.
The info for the engine serial number is here
http://chevy.oldcarmanualproject.com/models/engine.htm
Or in the pfd for 51 trucks in the GM Heritage archives
https://www.gm.com/content/dam/compa...olet-Truck.pdf
Scroll to the how to find the serial number section.