I think Masterton Homes is based in Newcastle-although they may have other state/national offices. The company was originally founded by Jim Masterton and is still family owned and operated.
A colleague of mine has recently used Masterton Homes to build his PPOR: he said they were ok.
And yes, if you drive around the CBD's of Sydney/Newcastle it does appear that the knock-down-rebuild projects are gaining in popularity.
Another nail in the coffin for house and land developers in the satellite suburbs?