Bodies and serial numbers were assigned to the various plants (domestic and overseas) by production scheduling at Willow Run with a follow-up scheduling at the plants to give them line assignments.
Domestic plants did not have their own separate serial numbering sequences; that's why the A, B & C on the door post serial number tags. Overseas plants had their own alpha sequence (J for example stood for the Kawasaki Japan assembly facility) but some had separate serial number tags (Leaside 1951 Kaisers had Kaiser-Frazer of Canada LTD and Rotterdam had their own tags; not sure about other locations as we're still doing this off survivors that were reported over the years).
This information can be found in KFOCI HANDBOOK Version 4.0 (the 2009 release) and 5.0 (which may be out yet this year) which is an update of the 4.0 release.
