Please see my comments above. Having asked local ecologists it seems that this is a hybrid of A vestita. The A cultriformis has a gland on the edge of the phyllode, this is not apparent on the phyllode of this plant. I have now added a photo of the phyllode.
Ah, so the other parent plant is unknown, although i would think A.cultriformis is the most likely in our region...... Does A.vestita and/or any other potential parent plant occur nearby?? :)