Guy, I believe these two cars are one and the same.... the "Singapore airline rally" was the name used for the London to Sydney that year...(1977 I think) and the car you posted pictures of still has these stickers attached, and it still has the "Caution left hand drive" stickers that it wore during it's time here in Australia (a local police requirement for LHD cars).... I am quite sure this is the same car that came to Australia...
If you look at your pictures and the one from the Italian magazine I have, there are some definite similarities...
Possibly they did make two, but my understanding was the car was specifically built for the London to Sydney rally, and I'm quite positive there was only one that competed in this rally (more of an endurance trial really)
Is it actually a 131AR chassis? I thought it was simply a regular 131 diesel that was "Abarth prepared"..
it was a long time ago that I saw the car in the flesh... but I recall it not being a 131AR bodied car...
SteveC