Those are very rare, limited edition brake drums only installed on the last 500 GNs produced and only on odd numbered vehicles. I have a set that I've been storing - waiting for the right opportunity to put them on ebay. I was hoping to get $5,000 for them but for you I'll let them go for $4999.99.
I wondered about the radio, too. My brother has an '86 Regal Limited with 25k miles on it. It is 100% original (except for the huge indentation in the nose from a round, immovable object - I suspect a bridge pillar). It has an am/fm cassette radio with amber illumination. I don't know if it was messed up at the factory or if the original failed early in its life and was replaced by the dealer with the incorrect radio. It's weird tho.
yep, it was promably a dealer warranty radio,those (all gm)cassette decks arent reliable...usually amber ment it was a pontiac,all others usually natural/green.