G'day folks,
I'm still inclined to favour the export model theory; Victa's policy then was to make store brands as variants of domestic model lines.
With different decals, and sometimes different colour scheme combinations to make them look distinctive, but always under
domestic VictaCode/Model numbers; they stated this on the index page of that 1991 'Instant Parts' book.
Which is available at
https://www.outdoorking-forum.com.au/pages/Victa/Models/Models_1970_1991.pdfSome of the 'big box' retailers who sold store brand Victas didn't carry even basic spares for them, back then. So Victa supplied the servicing dealers with a complete reference list, that covered all of the locally sold model variants.
Screenshot of the relevant Instant Parts book section is below.