They said that after 1978 it very tricky to trace as the system that Holden used Changed. Still possibly a sandman but as stated the GVM is a bit high..

Could this car be a base model that had a comfort/sports pack added?

Is it possible that the GTS dash, GTS guards, twin headlights are factory options?

Is it possible that it could be a base model with full length roof lining, bucket seats and console with these factory options?