my dad retired(earlier this year) from GM... I think he started working there in the mid 60's - started working on the assembly line - I showed him my assembly manual and asked him about it and he told me they never had anything like that to show the workers bees on the line itself.
After I showed him mine he asked me if they had one for the 47-'53 ones and I told him 'yeah and that one is organized' so he got one to use with his '53.
I dunno, maybe there are some other old GM line guys/gals floating around in here somewhere that can shed some light on it.
-W
