Hi
The Jackson Collection may hold information:

Jackson Collection. The collection was made by three generations of Sheffield surgeons, the last of whom was Arthur Jackson (d. 1914). It includes many papers of the Sheffield genealogist, William Swift (d.1874),
Reference JC/16/2
The Winnell family is certainly listed in this collection.


Also: www.wyjs.org.uk/archive-service/registry-of-deeds-and-family-and-local-history/
They hold one of only five surviving Registry of Deeds in the whole country. It contains memorial copies of over seven million deeds covering the years 1704 to September 1970.

What the deeds can help you with:

Tracing the history of a house
Tracing people who owned land or property before 1970
Getting certified copies of pre 1970 deeds for legal purposes
The Registry of Deeds can be used for legal purposes or for family and local history.

Angela

"but I'd like to get a copy of this book "A History of Allotments in Sheffield" by Margaret Boulton however it seems to be unavailable."
Amazon claim to have it for about £40.

Have you tried Sheffield Local Studies library to see if they have a copy of the book.