The image above is from an ebook that details the history of the company that manufactured the Esta Strap trousers worn by the Somerton Man.

The first thing you'll notice is the depth of the fob pocket and it's quite narrow. In the book itself, I think you'll find a reference to the seamstresses sometimes making custom pockets for customer orders. sadly there are no measurements provided but I think a reasonable estimation would be no more than 3 inches wide, given that that width is reasonably accurate, I would say the fob pocket was 6 or 7 inches in depth. That would make it quite difficult to find a tiny rolled-up slip of paper pushed all the way down to the bottom against the seam.

I am posting this because there seems to be some confusion about the existence of the torn slip which was in fact pushed well down into a pocket like this one, such that it was difficult to find. The torn piece did exist at the time, it was found by Cleland, in fact, it still exists, it's in safe keeping.