Complex sentence: Later, Moynihan swapped this Greek, round back bouzouki for a pre-war Gibson mandolin and then bought a flat back bouzouki from London instrument maker John Bailey, who had made it as an experiment after measuring an authentic bouzouki in one of London's Greek restaurants.
Split into simpler sentences: Later, Moynihan swapped this Greek, round back bouzouki for a pre-war Gibson mandolin. During a subsequent trip to London, he bought a flat back bouzouki from instrument maker John Bailey, who had made it as an experiment after measuring an authentic bouzouki in one of London's Greek restaurants.