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 Terowie Uniting Church building is now privately owned. It was built for the Methodist Church in 1882. A Memorial hall was added to the rear of the church building in 1919 in memory of members who were killed in World War 1. The church was closed in 1993.
No other details are known about the former church.
To find GZ
S33 09.0A0
E138 54.BC6
Where
A = number of glass segments
B = A minus number of iron crosses on front of church only
C = A minus number of long windows
CHECKSUM = 30