Punk Icon Portrait: Permission needed?

Dear Rich: I recently came up with an idea to do a portrait of a now deceased punk rock icon. The portrait is to be more a personality study/project for myself and I had contacted members of his family to find out if I could use various photos of dead person for this project. Family member of dead person to whom the photos originally belonged said she would allow me to use them but that dead man's estate would more than likely sue. Keep in mind this project is not-for-profit and the portrait would not be a realistic rip-off from an existing photo. Can I do this without obtaining permission? Can I show the work in a gallery if it is not for sale? We didn't have any painted portraits of deceased punks to illustrate your question so we used this brush-stroked non-portrait of Iggy since Iggy is eternal punk which is beyond deceased punk. The photographer is part of the Dear Rich Staff and we sure hope she doesn't sue because it would be a heartbreaking lawsuit of staggering complexity.

Right, you had a question. We're not sure why a relative said that the dead punk's estate will sue you. Is that because they own the copyright in the photos? (Owning copies of photos and owning copyright in the photos are different.)  If the portrait is derived from a photo, only the copyright owner of the photograph (usually the photographer) would have a claim for creating a derivative work (the portrait). That's what happened when the AP filed a lawsuit against Shepherd Fairey. But if you can dodge that claim under a fair use defense -- possible, but not certain depending on the similarities -- then you're probably okay unless you make and sell prints (and even that was excused in an Ohio case -- see this article for the skinny.