Just a bit of info re these labels.
7 Records was renamed Powderworks in September 1981 after 7 Records chief Ken Harding led a management buy-out. More info is on this Michael DeLooper pdf. M7 7records Powderworks
The label is certainly Powderworks, and 7 Records Pty. Ltd. (previously M7 Records Pty. Ltd., the MLF catalogue number is a carry-over from M7's system) would have been the distributor, but the label circumference says "Manufactured for and Distributed by RCA LImited", and I don't know when they came into the picture. M7 were certainly independent originally, and might have initially remained so when they became 7.
Powderworks Records is a record label established in 1977. Its headquarters are based in Brisbane, Australia. It is the home of Midnight Oil. Aside from recording, it made the Australian pressings of stuff on other labels, such as RCA, Columbia & Mute Records from 1978 to 1987