G'day folks,
The 'Monaro' mowers were not actually a model in the main 'Victa' range, but seem to be one of Victa's many 'storebrand' series of mowers, so labelled for a retailer buying group called 'NARTA'. The earlier ones had 'Made exclusively for NARTA by Victa Ltd' on the deck decal.

A few examples of 1970's-80's vintage Monaros have popped up on ODK. E.g. https://www.outdoorking-forum.com.au/forum/ubbthreads.php/ubb/showflat/Number/66711

We haven't been able to identify what 'NARTA' stands for, but one of their retailers was the Young's department store chain in the Southern NSW/ACT region.
Some of their 1970's ads are available through the NLA's Trove archive; http://trove.nla.gov.au/newspaper/article/110602591?

Cheers,
Gadge

"ODK Mods can explain it to you, but they can't understand it for you..."

"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."