Choong Jang
Though the order was slightly different, Choong Jang was still listed as the 14th Chang Hon pattern back in 1965. What appears to be an early version of Choong Jang is described in a Korean-only 1959 training manual with the name "U-Nam" (or Woo Nam).
When I first learned Choong Jang, there was something about it that really reminded me of Ge Baek. After looking over my notes, I found that both patterns tend to draw from Chinto/Gankaku and Chinte, with Ge Baek leaning towards Gankaku and Choong Jang towards Chinte. It also contains some movements from other patterns not mentioned in 1965.
As a side note, Choong Jong is known by some as the one with the "eye poke." The name of the pattern that this movement comes from, Chinte, translates as "strange hands" or "unusual hands," so this association is hardly new.
The following videos were used as reference:
ITF Legacy performance of Choong Jang.
Hirokazu Kanazawa performing Gankaku, Chinte, Hangetsu, Tekki Sandan, Kanku-Dai, Unsu (Shotokan).
Choong Jang opens with these two blocks in a sitting stance, similar to the section Po Eun borrowed from Tekki Sandan.
Choong Jang follows with a punch, then two of Chinte's eye pokes.
Choong Jang's ground section is interesting. When I started this project, I did not expect to find anything like this. However, Kushanku/Kanku-Dai (left) has a drop with both hands on the ground, and Unsu (right) features kicks from the floor. These floor kicks are done differently in different styles, but Kanazawa performs them similarly to how they appear in Choong Jang.
As a note, this floor kick existed in 1959's U Nam pattern, so it's clear that Choi had drawn from non-1965 kata early on.
Later, Choong Jang uses the twin palm pressing block in the same stance found in Hangetsu, and a large 180 turn drawing the hands together to the hip similar to the one seen in Gankaku.
The next section of Choong Jang closely resembles this sequence in Chinte, but with a 180 degree turn in the middle.
Unsu (center), which had the previous ground kicks, contains a similar hand position found here in Choong Jang. A similar position appears with a step backward in Jion (right).
The final movement of Chinte is a twin knuckle strike to the midsection, and a similar technique at head height is found in the final movements of Choong Jang.