A friend of mine also uses a CB77 2LS rear hub on his project.
It looks quite alright and brakes good according to him. To be honoust I didn't believe he has done much to the internals (never heard him mention something about this).
The hubs arent known for very good performance by the way, even though they are greater in diameter. A lot of CB50/77/72 race drivers switch to other brakes because of their performance.