How could I find out about my bicycle brand/model?
I share your doubt that it's a genuine Colnago.

I Googled "when was colnago clover leaf embossed" (you could try that with the .au removed also).

The hits show plenty of people asking such questions, and a couple of the hits seem to provide valuable answers


Unraveling the Mystery of the Colnago "Clubs"
How to identify a fake or genuine Colnago


Both of these suggest that without the "Club" embossing, it's not the genuine article.