Hi,
Working from the census returns. In 1841 Hawket Park was occupied by William Wallace, a merchant, b ca 1771 Ayrshire, and his wife, Margaret, born Dreghorn, Ayrshire, also ca1771. They don’t appear to have any sons who inherited the property, or at least wanted to live there. There were three daughters; Agnes and Jean who never married, and Janet who married Col. David Carstairs. Their son, William Wallace Carstairs (William & Margaret’s grandson) was born in India and grew up at Hawket. He became a wine & spirit merchant and died unmarried at Hawket Park in 1893. The informant was his cousin, Isabella Jane B ?? from Glasgow, he also left a will. William’s two maiden aunts, as their testaments on SP show died around the same time. If they had a brother, William, still alive at the time, he would probably be mentioned.
Possibly you already have this information?
Added: William Wallace of Hawket Park who died in 1851, also left a will (15 pages) you can download it for 10 credits
http://www.scotlandspeople.gov.uk/Search/results.aspx