The group had used fake names to hide their true identities, secured business by misrepresentation, knowingly delivered defective services and persuaded customers to pay substantial deposits for substandard work, according to Trading Standards.
There is no suggestion Ms Brown, who died in 2022, was aware of the group's illegal activities.
Zulkernan Mahmood, 36, of Bradford, West Yorkshire, and Rehan Yousaf, 47, also of Bradford, both admitted fraudulent trading and participating in a fraudulent business.
Jonathan O'Grady, 37, of Bridlington, East Yorkshire, was found guilty of fraudulent trading and participating in a fraudulent business.
David Goody, 54, of Bradford, admitted participating in a fraudulent business.
The defendants were sentenced at Leeds Crown Court on Friday following an investigation led by Trading Standards officers hosted by York City Council.
Lord Bichard said: "These men left many people with extensive remedial works required at their homes; some were left living in structurally unstable properties with no viable means of repairing the damage done due to the financial losses they incurred."
