G'day Max, Paul and Norm I feel Max's explanation of a typo is the best bet here.
I'm less sure that manufacturers were importing Tecumseh engines than that they were using Tecumsehs imported by James Kirby.
In any case it appears they were fully imported in the early days, and not made locally.
A note on Carter and Turner. I'm sure this came about because of some deal done between James Kirby and Rene Turner - at a high level.
In the attachment below, Graeme Plaw, a Turner Engineer, discusses Turner. Note that he was unaware that the Carter actually was produced and marketed through Kirby Sales Pty Ltd.
[Correction: I mean, that he was not aware the Carter made it to production].
It's pretty clear that Carter was a Kirby project.
Plaw confirms that all Turner bases were made by Swift Foundaries. I think Supa-Swift was their separate mower division.
Many thanks to Max for the research, and all for the great conversation.
