Im no student of Isalmic ARt but if you recall the huge influence that Islamic and "Egyptian" art had on architecture and monuments in the US in the Post Civil War era. Id look up "Havilland" as a designer of several monuments influenced by Muslim art.
In Jannsons "History of Art" is an entire chapter devoted to Islamic art and why there ARE NO WELL KNOWN it was a blasphemy ISLAMIC portraitists. There are one or two Muslims who were part of the Abstarct Exression movement in modern art. I do not think that thir "Muslimity" was any force that directed their art.
Sorry Im no help but, if you find some actual portrait artists , please post them and we can share in the information.