**SOLD**
I believe these to be original GM service replacements - they do not have the 'O' stamped on the flange, but the stampings and quality of chrome are very similar to the assembly line valve covers on my Z/28. Very nice overall, but some scuffs and light corrosion in isolated areas. Nevertheless, these will look great on nearly any quality of car. Looking for $100 plus shipping for these. Pics below:

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