Hello Kye

The "4" is for 4-stroke.

These bases (and variants) spawned a number of store brands across Australia.
I do believe I am the first fool to identify what it is ... [drum roll] ...

It's a Hurricane 4 (the same people who made the Hurricane engine).
Date: early to mid-1960s.

This does not necessarily mean it was sold as such.

Most interesting feature: the central height adjuster.
p.s. another one of Patrick's Kirbys.

Hope this helps.
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Jack
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