Fact about this area: The Battle of Naseby was the key battle of the first English Civil War. On 14th June 1645, the main army of King Charles I was destroyed by the Parliamentarian New Model Army commanded by Sir Thomas Fairfax and Oliver Cromwell.
Read more about the Battle of Nasesby via this link
To find the cache you will need to visit the four listed waypoints and obtain values for 'W', 'X', 'Y' and 'Z'.
Waypoint 1: Find out who planted the tree. The person's surname has how many letters? The answer equals W.
Waypoint 2: You are in the cemetery. Find the grave of John Cook. He "departed this life on the X6th Day of 1813." Note: the coordinates will take you to the centre of the cemetery; you will have to search for John Cook, or guess. 
Waypoint 3: The Naseby Men: Mr. Westaway fell in The Great War. How many letters are in his first name? The answer equals Y.
Waypoint 4: The first number shown on The Market Cross plaque equals Z.
Use the values obtained to get to the following coordinates:
N 52° 23.(W+X)(Y-Z)(W+Z)
W 000° 59.(X+Z)(Y-X)(X+Y)
If anybody would like to expand to this series please do, I would just ask that you could let Sadexploration know first so he can keep track of the Church numbers and names to avoid duplication.
To view the church micro stats page, please click here