Mike,
It is most likely Canberra Gem, a cultivar which I think originated as a G. rosmarinifolia x G. juniperina cross. This Grevillea naturalised in many parts of the Mount Majura and Mount Ainslie NR, but most have been removed in the last 15 years as they were non native and considered by the ACT government as a fire hazard. There are a couple of plants left in JRHP. They do provide great habitat for honeyeaters and their removal has caused a noticeable local decline in honeyeaters since then.
Regards,
John Briggs