Great post. Last summer (2019) I flew out and attended Chrysler Nationals (PA) for the 50th anniversary of the A12. I got to meet some other A12 owners AND...found an original A12 6bbl base! I found three (legit bases) for sale, which amazed me. The cleanest example just so happened to be owned by the most reasonable and down to earth of the sellers. Before I purchased, I took a bunch of photos and went back to the A12 Tent and asked a few guys who knew better than me, to make sure the base I was considering was the real deal. They pointed out what to look for and assured me that I was buying an actual 69.5 base.

I won't repeat what other's have mentioned already, but there are indeed things to look for to be certain you're buying an original, if that's what you're looking for. For me, I just didn't want to buy a fiberglass unit, so why not look for a good original, especially considering the cost of a new steal recreation.