Can be Australian delivered KMGC210/211 or Japanese Delivered KHGC210/211.
Also known in export markets and Australia as Datsun Skyline GL or Datsun 240K.
Series ran from 1977 - 1981.
If you know anyone that owns one of these or maybe it's just sitting out in someone's backyard, let me know, all info appreciated.
Pictures for reference of model:




Cheers,
Socrates.