indieWIRE has this article (with photos) on the almost 65-year-old Dame Helen Mirren posing nude for New York Magazine.
But don’t overlook the 1969 film Age of Consent, where Mirren plays about a third of the movie naked, and the other two thirds wearing nothing but the most threadbare and easily discardable short cotton dress.
Shot when Mirren was 24, she plays a teen wild child abused and neglected by a hateful aunt in the remotest Australian coastal settlement. James Mason, artistically blocked and on the run from his fame as a painter, shows up, and she becomes his muse. Age of Consent is available on DVD, Netflix streaming and occasionally on TCM.

Sounds like my kind of movie! Thanks for pointing it out. I’ll def keep my eyes opened for it on TCM.