This collection of caches has nothing to do with the Church Micro series in the UK. Given that the Australian 2016 census indicates that No Religion and Jedi Knight are the fastest increasing classifications of the optional religion question "What is the person's religion?" it is not surprising that there is surfeit of empty churches that have been repurposed.
Some history
The former St Peter's Lutheran Church, Peterborough property is now privately owned. The first Lutheran services were held in private homes from about 1877, with the church opened on 12/7/1885. No other details are known.
To gather the info for GZ you will need to find the street address ABC and the info on the stone plaque visible near the top of the former church
D = second digit on date on stone plaque
E = number of letters in the second word top line plus A
F = third digit on stone plaque plus A
S 32 58.CEB
E138 50.BDF
CHECKSUM = 30