Wait, I thought this already happened a few years ago... I was trying to help someone restore the banana2 file but couldn't figure it out. Sometime later, someone else did it successfully with the pre-release version of GraphiCraft used at the launch event, which was the only program that could handle it.
It looks like another group now did the exact same thing, only through a much more circuitous route...
Yes, you're right!
I was able to open the Andy's files running a beta version of Graphicraft, the same used by Warhol in 1985, with a pre-release kickstart on my Amiga 1000. I did it in an afternoon and it happened some years ago...
The owner of the disk is Don Greenbaum. In 1985 he was the chief financial officer for Commodore International and he got the disk directly from Andy Warhol during the days of the Amiga launch at the Lincoln Center. I met Don here, on this forum: he was looking for someone or something who could help him to open the Andy's files 25 years later...
I'm really glad Matt_H remembered this!
Alessandro