William Chow passed away around 1987. Most of his senior black belts like Adriano Emperado and Ed Parker had long since started their own subsystems and organizations.
The two main people who claim to be heir to his system are: Sam Kuoha, who has a Kara-ho Kempo Karate Association, and Bill Chun Jr., who has the "Go Shin Jitsu Kai Kenpo" organization. These were 2 of the names Chow used for his style, along with "Shaolin Kenpo" and a few others. When Ralph Castro broke away from Ed Parker, he adopted the Shaolin Kenpo name because Chow was no longer using it.