oh yeah you are right those are IMPOSSIBLE to swap.
tin NEVER gets changed. no one has ever mis ID'd a machine with wrong tin. :)
HALF or MORE of the fords from 43-64 i've EVER looked at wer emis id'd. most as jubilee!!
one of the 850's i have was an 801 according to the owner.. even after I showed hom the 850 ont he tranny. he actually got mad. :)