The posted co ordinates take you to some information that you need to use for the following formula .
Church Street = A
Spalden Almshouses number = B
Old Grammar School number = C
Pegge's Almhouses number = D
Smiths Yard number minus Former Gas Works number = E
Ginger Bread Shop numbers minus Old Police lock up = F
CHECKSUM ABCDEF = 41
The cache can be found : N 53° 00.A B C W 1° 43. D E F