Hi Scott and thanks for showing these. Greg is correct: these are Peter Goss signed production pieces from the Jam Factory in Adelaide in the mid-1970s. There is more detail in my other post for which Greg has given the link. I provide some further information about Peter Goss in a blog article - see the link in my signature block below.
A hint on photos for the GMB. You can make them considerably larger, and hence clearer for those of us with older eyes and still be below the limit of file size, if you use a plain background.
Trevor