Thanks for the suggestion. Does PDF Squeezer batch compress? That would be of extreme importance of course.
I have PDF Expert which allows compressing too. In the case of the newspaper PDF the original size is 3,4 MB and compressed in PDF Expert to lowest quality it is 3,2 MB—which isn’t worth the effort at all. And not surprising because the Kindle newspapers contained mostly of text and very few images (you could get them without extra fee via mobile net).
By comparision, the ePub file of the same newspaper has 1,3 MB. And the PDF, generated by Calibre, does not even have a ToC.