The model you're referring to was numbered R770 "City of Knox". (The fleet
numbers of the real R class were R700 to R769). There was also a model of
R707 with "HMAS City of Melbourne" name plates, as there was a small
flamewar going on over the "battleship" boards at the time.
I've also seen models of V/Line G, N and P classes in VR blue and gold.
AMRM readers will also remember Bob Cooke's famous tuscan 8101.
Cheers
Davic