Kevin may have built for Cecil Walker for a while. I think it's all a bit of a cosa nostra for Aussie builders. I've got a Paconi, Cecil Walker, Kenevans, and a Conceicao in the stable. Always keeping my eye open for a nice local frame (that fits me).
Meaning no disrespect to others who built for these makers under license or whatever agreements, the ones I can put names to are:
(* means still making stuff as far as I know)
Paconi (Kevin Wigham)
Cecil Walker (Cecil Walker)
Hillman (Gordon Hill)
Bundy (Bundy brothers, but pretty much every Aussie builder has built for them)
Clamont/Gefsco (Geoff Scott)
Europa (John Abeni)
Kenevans (Ken Evans)*
Beretto (Brett Richardson)
Euro (Brian Hayes)
Frezoni (Joe Cosgrove)
Hoffy (Eric Hendren)
Baum (Darren Baum)*
Van Werkhoven (Andrew Van Werkhoven)
Llewellyn (Darrell McCulloch)*
Kumo (Keith Marshall)*
Kypo/le Kypo (Rob Kypriotis)
Conceicao/Albion Cycles (Frank Conceicao, but all built by others under his name I believe)
SorenSon (?)
Ciombola (Michael Abel/Wayne Roberts)
Wayne Roberts (Wayne Roberts)
Malvern Star (everyone and anyone, even carbon of late)
Tamari (?)
Plus there's a bunch of small volume builders doing awesome stuff. A whole slew of Aussie names have come and gone. This is by no means even close to complete!