I am no Guru in this, but I think you can tell the manufacturing location by the serial number of your ride.
Please read the "reference" chapter of the excellent P15-D24 info pages...
http://www40.addr.com/~merc583/mopar/framesets/referenceframeset.html
Further models in the below link...
http://www.ply33.com/misc/vin#decodeNotes
Factories, P19, 1950:
Detroit from 18,041,001 to 18,119,094;
Evansville from 24,012,001 to 24,035,538
Los Angeles from 28,004,001 to 8,009,848
San Leandro from 28,503,501 to 28,511,177