Door hinge dates

I am looking over the door hinges and not sure if they are correct. The car build date is 12/21/64

They read as follows

Drivers side

Upper 31847-ALH S.P.C. ~ 10

Lower 55L S.P.C. ~ 10

Passenger side

Upper 31846-ARH S.P.C.~ 3

Lower 52R S.P.C. ~ 8

Thanks