I'm looking into a used Panasonic, and I'm hoping someone can help sort out a little confusion over the frame material. The guy selling it says it's a custom frame from the 80's. I'm pretty sure that means it was custom *painted* from the "Panasonic Individualized Custom System" and not actually a custom frame. It's equipped with Shimano 600. I was expecting this to be a steel frame, but they guy says the downtube is marked "aluminum."

I don't have any reason to doubt this guy's integrity, but I thought all the frames would have been steel during the "PICS" era. Before I drive an hour just to check out the bike, I just wanted to see if I'm missing something here, like maybe Panasonic was indeed pumping out aluminum frames at that time or the "aluminum" label somehow refers to something other than the frame.

Thanks in advance for any input.