I disagree. I remember the '71 release well & the HQ grille badge was always multi coloured.
Also there is only one part no. from '71 to '74, no change. GM-H always changed part numbers no matter how small the change in production.
I think it's a bit like the FB/EK horn buttons, where they where supplied by 2 (or more) outside suppliers. They started out all the same colour, but due to different production methods & slightly different plastic compounds, they have aged differently. Now 50 years later the badges from supplier A, looks different to the ones from supplier B.
Dr Terry
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