G'day there Rob, and a warm welcome to the ODK Forums.

Victa ride-ons have always been US-manufactured rebadges, so it would be no surprise that very similar/identical models would be sold as 'house brands' by the US big box chain stores. Sears, Montgomery Wards, and so forth.
The earliest Victa ride-on models back in the 1970's were made by MTD, and this continued until fairly recent times, when Noma and Murray came into favour.
Rob, is there any sign of a model details decal, located beneath the seat?