Aloha...I know a family with the last name Seui; however, they live in Nuuuli rather than Mapusaga. One of the Seui's is Pastoring a Methodist Church at Waianae, Hawaii. His name is Faulalo Seui. Maybe there's a connection somewhere since their last name is Seui, and also a Methodist family. Well, I hope that will help you with your search for the Seui's Family in American Samoa...