The North Mymms History Project (www.northmymmshistory.uk) has a wealth of information about the local area including St Mary's.
Below are some links to articles about the church.
Restoration of the Belfry at St Mary's, North Mymms, 1985
H M Alderman on the Bells of North Mymms
Articles about the bells, written in 1950 and '51 in the parish magazine
A Short History of the Parish Church of St Mary, North Mymms
Compiled by local historian and teacher Dorothy Colville in 1962.
Historical Treasures of the Parish Church of St Mary, North Mymms
A series of articles from 2004 and 2005 Parish magazines
North Mymms WWI and WWII War Graves
The North Mymms War Memorial
The Booth Tomb, restored in 2018.
Mason Marks of St Mary's Church, North Mymms
The Mass Dial of North Mymms 1584
Witch Marks at St Mary's: Grafitti or Apotropaic Marks?
The Medieval Mysteries and Curios of North Mymms Church
A Short History of the Knolles and Frowick Families
Vicars of St Mary's since 1237
Reverend Leonard Buxton of St Mary's North Mymms
Serving North Mymms through WWII