Hello Kye,

I would think so (assuming the record is accurate).
It was not uncommon for makers to offer various engines.
There would have been advantages in offering an Australian-made engine.

If late 1950s, it can only be one type of Kirby 2-stroke:-
https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=59415

Hope this helps.
-------------------------
Jack