I haven't done too much research, the information I have is generally what I have been able to get from other people.
The Madill's of my family are my grandfather's ancestors (my Mum's Dad).
See the following link, however some of the information is out of date. Though the creator/researcher of the site (Jason Potts) is probably the best one to get in contact with re: Madill family tree. http://www.potts.net.au/tree/misc/surnames.htmhttp://www.potts.net.au/tree/misc/surnames.htm
I'm not sure how much information you have, but my direct line from my grandfather, Fred Madill (in the newspaper article in the 2nd link) is David Madill, Thomas Madill, Mathew Madill. I believe David was about 10 years old when the family migrated to Australia. David had 3 wives (I forget the names of the first 2), but the 3rd one was Abina Maude Lynas. David b. 1855 d. 1932 (about). I believe they were all farmers. David was certainly a farmer in Australia (in a very small town in the state of Victoria, Undera, near Shepparton). His son, Fred (my grandfather) ran the dairy farm until the mid-1960s and my Uncle (my grandfather's son) still owns the farm, though the lack of rain is making it quite hard.
I can't be more specific as the notes I have are currently in transit as I have moved interstate.