[Mr70]

I've only seen that reflective GM mark of excellence on pre 70 models originally.
Beginning w/70 production they used the horizontal Blue certification label w/clear overlay showing the full VIN# & assembly date typed onto it.
The tire psi label would've been applied above the lower Blue certification label I believe.
I think early assemblies got welded on hinges,with later receiving bolt on,but I could be wrong...