Did you have any luck with this search - I too am looking for the Rhodesian/Zimbabwean branch of the Hussey clan.
It's my understanding that my great grandfather Dudley Hussey had a brother who moved to Bulawayo.I think his name may well have been Pat.(FamilySearch.com comes up with Patrick as a child of Thomas Hussey and Mary Kelly, my great, great grandparents)
What gives me more hope is that your Pat's eldest was called Dudley.That is the tradition in my Hussey family, to name the eldest boy Dudley!
If you've got any further info, I'd love to hear it.Maybe I can be of some help to you also.