In October of 2013, Shinkikan Dojo hosted a seminar taught by Steve Stark. Mr. Stark is one of Oyata Seiyu's most senior direct students. He began training in Oyata Sensei's art in 1969/1970, and became a personal student of Mr. Oyata in 1977. His fascinating story of traveling to Okinawa to find Mr. Oyata, and training with him back in Kansas, can be read in his book "Quest: The Ancient Way, My Life Experiences with Taika Oyata". It's an entertaining, informative read and is highly recommended to all serious students of Oyata Sensei's art (as well as practitioners of Okinawan Karate in general). Mr. Stark is still actively training and teaching.
Mr. Stark's book can be purchased through Ryu-Te Supplies: http://ryu-te-supplies.com/
picture from 2013 seminar with Steve Stark