The campaign and promo theme was "Colour Machine". This was 1 year after the start of colour TV transmissions in Australia so Channel Seven, like all the networks, was heavily pitching promos that involved the colour theme. It followed Channel 7s "Colour your World" promos of 1975. This promos featured a variety of local and overseas talent as well as the public, who were more than happy to flash the famous 5 and 2 at occasion!
The first clip below shows Agnetha and Frida very briefly at the 14 second point. Others in that film are Olivia Newton-John, Spike Milligan, Shaun Cassidy ("Hardy Boy" and half-brother of David) and Bryan Ferry.
The second clip below is a montage of several clips but at 1 minute 11 seconds, there is a Colour Machine promo entirely of ABBA who are also seen flashing the "5" and "2". The second one features the same very brief clip of Agnetha and Frida as featured in the first clip.
Whilst I'm not sure that these were filmed especially for Colour Machine, I've included them here as they do have different footage to any seen in any other entry.
YouTube clips c/o morsayoagain