I have a theory about rear hood hinge color on 71s. My car, which has been repainted, but is still pretty nice, has black hood hinges. It is late production, chassis no. 9111102572, which makes it a Porsche built coupe. Also, it has (I should say had, because it's mostly removed) factory air conditioning. The hood hinges are different from standard ones inasmuch as they have holes where the rear condenser and hoses mount. Could it be that Porsche continued to use black hood hinges that it had on hand for A/C cars later into 1971 production?

Inquiring minds want to know.