I'm sure I heard that a UK PPL IMC who wants to fly symulated IMC (ie, a VFR flight) only needs a responsilbe person sitting next to him/her. That means you're granny if you want! Can;t be right can it, but I'm sure that any PPL will do (pick one with good eyesight, bags of patience and an ability not to grab the controls when they see another a/c that's 5 miles away.
Don't know about N registered a/c - not much help really, am I?