Here's the Amazon JP rough translation:
[About the Japanese version]
This work was theatrically released in Japan on December 10, 1977 ahead of the whole world, and the main part at that time was a version of about 129 minutes.
After that, the version released worldwide in 1978 except for the UK was the main part of about 123 minutes, and since then
it has been released on various media such as laser discs, VHS, DVD, Blu-ray, etc. It has been said that it is impossible to see the 129 minute version.
Under such circumstances, the material of the main part of the 129-minute edition was miraculously discovered in Japan, making it possible to create and release HD masters from negatives.
However, as the stance of the original rights holders overseas, the final version of “Capricon 1” is 123 minutes, and now there is no 129 minute version, so this release license is unusual. Yes, probably the first and last commercialization.
The main differences between the 129-minute version and the 123-minute version are whether the spacecraft docks on Mars landing, whether there is a date telop, and other parts that are finely cut.