I've never heard of Yoon Kwe-byung (Yoon Ui-byung) studiying any chuan-fa. His teachers in Japan were Mabuni Genwa and Toyama Kanken.
Yoon Byung-in: He was born in 1908 and grew up in Chang Chun, Manchuria, in the outskirts I believe. In a meeting in 2005 with his family, they said he trained under a Mongolian instructor from youth until he left for Nihon University in Japan around 1938. They didn't give a name though. They also mentioned that most of the chuan-fa instructors around Chang Chun were from Mongolia back then. One of Yoon Byung-in's students, Hong Jong-pyo, had a student that is a medical doctor. On a business trip to Chang Chun (there is a large Korean community still there) about 15 years ago, he saw chuan-fa students practicing in a park. They were practicing a version of Jang Kwon very similar to the version we still practice in Chayon-Ryu. They call their chuan-fa style "Pal Guek Moon."
Grandmaster Kim Ki-whang (dec. 1993) confirmed that he witnessed Yoon Byung-in beating up a group of karate students from Toyama Kanken's karate club at the university. There was lots of animousity from Japanese students towards Korean students on campus. Apparently, Yoon Byung-in was defending a classmate from getting beaten up. The karate students told Toyama Kanken about being defeated by a Korean using some martial arts, but it wasn't karate. Toyama invited Yoon to visit the karate club. Yoon began learning karate from Toyama at that time.
When Yoon located to Seoul following WWII, he taught both the chuan-fa he studied and the karate from Toyama Kanken in one curriculum. Toyama even recognized Yoon as a 4th Dan and the YMCA Kwon Bup Bu representative. (4th Dan was recognized as 2nd in rank to Toyama by Toyama himself at this time - Toyama was 5th Dan then). You can find Yoon listed as 4th dan in Toyama's early instructor's directory with (Korean) next to his name and listed as 5th Dan in the later edition.
As for what was taught from Chuan-fa? This portion is a major subject of the curriculum in Chayon-Ryu. Grandmaster Kim Pyung-soo has been preserving and teaching this part in Houston, Texas for 40 years now. Two forms from the old chuan-fa curriculum has been lost though. One form was called Cheung Yong Kwon, meaning, "Fist of the blue dragon." Another was called Kum Kang Kwon, meaning "Mightly Power. " Later this same name was used by the KTA for a new TKD black belt form. It is not the same form. Grandmaster Kim says that he saw Grandmaster Park Chul-hee demonstrate Cheung Yong Kwon at the demo from the linked photo below, but Grandmaster Park and everyone else didn't teach it anymore. So, he never got to learn it himself.
http://www.kimsookarate.com/gallery-old-days/1stdemo.html
Other chuan-fa form names fthat are preserved from this lineage include: Dan Kwon, Jang Kwon, Doju San, Taijo Kwon, So Ho Yon, Palgi Kwon, Han Son Dae Ryon. There are other partner drills, but these are the forms still preserved.
The link is to some photos of Grandmaster Kim Pyung-soo demonstrating Jang Kwon and So Ho Yon in Dallas, Texas in 1968. (Side note: I demonstrated these forms also when I visited Master Stoker's dojang a few years ago)
http://www.kimsookarate.com/gallery-first30/uskc68.html
More about Yoon Byung-in:
http://www.kimsookarate.com/intro/yoon/Byung_In_YoonrevMay3.pdf
http://www.kimsookarate.com/intro/yoon.html
R. McLain