I plead ignorance.
Not much experience with the long toms of South Australia.
Australian punctures OS for the states remain a bit of an enigma, esp. for prices. (Usually 2 x catalogue)
Your stamp 6d Blue Green of 1904, could have been used anywhere in Australia.
South Australia ceased overprinting Officials in September 1903
They do exist, scroll down here, and check your punctures with the scans......https://millenniumauctions.com.au/s...t_auction=16
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