I've been reading that a lot lately. My research leads me to believe this system is much more modern that a 70's system. The platform might have been designed in the late 70's but the missiles, radar and comm gear are more likely late 80's tech if captured from Ukraine forces but 90's or newer tech if they came from modern Russian forces.
Difficult to say. We know Russia provided T- 64 tanks to the separatists and they’re from the 1960s.