I can certainly shed some light on that for you.
There are two Korean Volumes of the Soo Bahk Do Dae Kham. Volume 1 is largely similar to the
English version, but it does not stop at Bassai. It include Jinto, Ship Soo, Lohai, and a few other of the higher forms. Of course, it is 100% in Hangul, so unless you read fluently both Hangul and Hanmun, you'll have problems with reading it. There are plenty of pictures though!
The Korean Volume 2 is the one that everyone talks about. It has illustrations and text for all 6 of the Yuk Ro hyung. This is the only place in print with all 6 Yuk Ros. The English version has only 3. But of more interest are the Ship Dan Khum. These are the 10 "lost forms" that you hear so much about. The rumor/legend/story/version I heard is that GM Hwang Kee taught the Koreans the Ship Dan Khum and taugh the Americans the Chil Sungs and Yuk Ro, in the hopes that it would unite the two countries and force them to come together. But to the best of my knowledge, that hasn't happened. My Korean Sa Bom Nim does know all 10 Ship Dan Kuhm....but he's in Korea and didn't teach me before I left. He does not know all of the Chil Sungs and Yuk Ros though....which lends a bit of credibility to the story. He also has the books though....
Unfortunately, no, they are not available. The Hangul versions were a limited run printed and from what I've found the people who have them are holding on to them. I've been on a search for literally years and have offered large sums, but I still don't have either. When the Dae Khum (Volume 1, in Hangul) came up on E-bay (once in the last 3 years), it went for over $500.