If you're looking for Newton's Sunday Observer Comics supplement 9 March 1975 you're looking for two supplements.
Allow me to illustrate - this is page 1:
Followed by pages 2 and 3:
And this is the back page:
Things appear to be as expected. The first page is dated and features The Fantastic Four; Spider-Man makes his debut as promised the previous week; and the Conan the Barbarian and Doctor Strange features round out the Marvel quota for the week.
However, when you turn to the centre pages 4-5, this is what you find:
That's right - there's another inner supplement also dated 9 March 1975! And it prominently features Spider-Man from his appearance in The Amazing Spider-Man #1.
Sure looks like someone stuffed up... Not that kids would have complained - after all, a bonus is a bonus... and the next couple of pages offer more goodies:
And then we have page 8 of the second supplement:
Of course the second inner supplement is actually the first in the reading sequence - and there are pages missing between the segments. When Newton stuffed up they didn't do so by half measures.
I'm lucky to have seen the inner and outer supplements bound into the Sunday Observer, courtesy of the State Library of Victoria. Imagine trying to make sense of the publication dates and sequence if these supplements turned up randomly, divorced from their context. And in case you're wondering, there was indeed a Comics supplement in the newspaper the following week.