Reporting Plagiarism in Older research Disclaimer: I apologize for the vagueness of this post as i do not wish to speak negatively about anyone particular on a public forum.

I've been doing research on a specific topic looking at two articles, one a book published in the 1991 and the other an article published in 1964 in an academic journal. 

I noticed that the procedures followed in both papers are very similar and the method seems almost identical, However the 1991 book makes no reference to the 1964 paper and claims its model is new.

I find this incredibly dishonest, its possible that I'm an idealist with reference to a highschool understanding of academic honesty but I think at the very least it should be reported to the publishers.

How do I report possible academic plagiarism to publishers? Is such an activity worthwhile?
The perception of plagiarism has evolved significantly along the years, and practices that are not tolerated nowadays were instead not unheard of in the recent past. I recall seeing several papers from the 1980s and 90s replicated almost identically in different venues, without any cross-citation or copyright notice.

Moreover, bibliographic searches in the past were not so easy, and the authors of the most recent work may have found the same result independently and missed the older work.

Since almost thirty years have now passed from the publication of the second article, I'd ignore the matter: nothing really useful would come out by bringing it up.